HCU PHD CS 2018 June
Question 1 
Random sampling is helpful as it is
Reasonably accurate  
Flee from personal biases  
An economical method of data collection  
All the above 
Question 1 Explanation:
A method of selecting a sample (random sample) from a statistical population in such a way that every possible sample that could be selected has a predetermined probability of being selected.
Question 2 
Type I Error occurs if
The null hypothesis is rejected even though it is true  
The null hypothesis is accepted even though it is false  
Both the null hypothesis as well as alternative hypotheses are rejected  
None of the above 
Question 2 Explanation:
Rejecting the null hypothesis when it is in fact true is called a Type I error.
Question 3 
The Ftest:
is essentially a two tailed test  
is essentially a one tailed test  
can be one tailed as well as two tailed depending on the hypothesis  
can never be a one tailed test 
Question 3 Explanation:
An Ftest is used to test if the variances of two populations are equal. This test can be a twotailed test or a onetailed test.
The twotailed version tests against the alternative that the variances are not equal.
The onetailed version only tests in one direction, that is the variance from the first population is either greater than or less than (but not both) the second population variance. The choice is determined by the problem.
The twotailed version tests against the alternative that the variances are not equal.
The onetailed version only tests in one direction, that is the variance from the first population is either greater than or less than (but not both) the second population variance. The choice is determined by the problem.
Question 4 
When two or more successive footnotes refer to the same work which one of the
are the following expressions used?
et al.  
op. cit
 
loc. cit  
ibid 
Question 4 Explanation:
Ibid meaning "in the same place", commonly used in an endnote, footnote, bibliography citation, or scholarly reference to refer to the source cited in the preceding note or list item. This is similar to īdem, literally meaning "the same", abbreviated id., which is commonly used in legal citation.
“Et al.” is a scholarly abbreviation of the Latin phrase et alia, which means “and others.” It is commonly used when you don't want to name all the people or things in a list, and works in roughly the same way as “etc.”
“Et al.” is a scholarly abbreviation of the Latin phrase et alia, which means “and others.” It is commonly used when you don't want to name all the people or things in a list, and works in roughly the same way as “etc.”
Question 5 
Suppose a random sample of 100 objects was considered and their widths were
measured. The mean width of the sample was 64 inches and the standard deviation
of the sample was 5 inches. Assume that the widths of the objects are normally
distributed. Which interval below includes approximately 95% of the widths of the
objects?
63 to 65 inches  
59 to 69 inches  
54 to 74inches  
Cannot be determined from the information given 
Question 6 
A random sample of 1000 measurements was taken. Assume that the 99% confidence
interval for the population mean was 68 to 73 (in arbitrary units). Now, if a
95% confidence interval is to be calculated, then
The 95% confidence interval will be wider than the 99%  
The 95% confidence interval will be narrower than the 99%  
95% and 99% confidence interval will be the same  
One cannot make a general statement about whether the 95% confidence interval
would be narrower, wider or the same as the 99%

Question 6 Explanation:
For a given sample, the 99% confidence interval would be wider than the 95% confidence interval, because it allows one to be more confident that the unknown population parameter is contained within the interval.
Question 7 
Having two sets of data, we wish to compare then:;catering.
Which of the following statement/s is/are TRUE?
I. For approximately equal average values, the one with a higher standard deviation is more scattered
II. For approximately equal standard deviation values, the one with a higher average is more scattered
III. For approximately equal standard deviation values, the one with a lower average is more scattered
I only  
II only  
Both I and II  
Both I and III 
Question 7 Explanation:
For approximately equal average values, the one with a higher standard deviation is more scattered
For approximately equal standard deviation values, the one with a lower average is more scattered
If both the averages and standard deviations differ much between the series, we can compare scattering using the coefficient of variation
For approximately equal standard deviation values, the one with a lower average is more scattered
If both the averages and standard deviations differ much between the series, we can compare scattering using the coefficient of variation
Question 8 
The result of a statistical test, denoted p, shall be interpreted as follows:
the null hypothesis HO is rejected if p < 0.05  
the null hypothesis HO is rejected if p > 0.05  
the alternate hypothesis HI is rejected if p > 0.05  
the null hypothesis HO is accepted if p < 0.05 
Question 8 Explanation:
For typical analysis, using the standard α = 0.05 cutoff, the null hypothesis is rejected when p < .05 and not rejected when p > .05. The pvalue does not, in itself, support reasoning about the probabilities of hypotheses but is only a tool for deciding whether to reject the null hypothesis.
Question 9 
The Confidence Interval for the mean, calculated for a series of values, has the
interpretation:
The true mean, the one that approximates the populations mean, is almost
certainly inside the confidence interval
 
The true variance is almost certainly ~inside the confidence interval  
The true median is almost certainly inside the confidence interval  
None of the Above 
Question 10 
When searching for the best fit line for data using linear regression, which of the
following approaches commonly used?
Logarithmic Loss
 
ANOVA  
Parametric Estimation  
Least Square Error

Question 10 Explanation:
The method of least squares is a standard approach in regression analysis to approximate the solution of overdetermined systems (sets of equations in which there are more equations than unknowns) by minimizing the sum of the squares of the residuals made in the results of every single equation
Question 11 
The probability of getting Five Mondays in a 31 day Month is:
1/7  
2/7  
3/7  
None of these 
Question 11 Explanation:
There are a total 7 possibilities,because a month can start with any of the 7 days of the week .But there are only 3 possibilities of getting monday 5 times , if the month either starts with saturday or sunday or monday. So the required probability is 3/7.
Question 12 
A married couple has two children. One of the children is a girl: given that having
either girl or boy is equiprobable then the probability that the other child is also a
girl is:
1/3  
1/4  
1/8  
None of these 
Question 12 Explanation:
Given that out of two children one is definitely girl.So the total possibilities are ,
{girl,boy} ,{girl,girl}
So the probability that another child is also a girl is =½.
So the probability that another child is also a girl is =½.
Question 13 
How many 0's are at the end of 20! when represented in octal?
4  
5  
6  
7 
Question 13 Explanation:
Count up the number of factors of 5 and the number of factors of 2 in 20!. Since we get a zero for every pair of factors 5x2, then the minimum of these will answer your question. More simply, 5 happens less often as a factor (since it's bigger than 2), so we need only count up the number of 5's. In particular, there's one each in 5,10,15,20, so there are 4 zeroes at the end.
Question 14 
A mineral collection contains 12 samples of Calomel, 7 samples of Magnesite, and
N samples of Siderite. Suppose choosing at least 15 samples from the collection
guarantees that you have 6 samples of the same type of mineral. What is N?
6  
2  
3  
4 
Question 14 Explanation:
If the value of N is 4 then choosing at least 15 samples from the collection guarantees that u have 6 samples of the same type of mineral, because in worst case choose 4 from each collection then we have 4 samples of the same type of mineral and now siderite is finished and we have to select from remaining two samples .Now select 2 from 1 sample and 1 from other in worst case. Now we have selected 15 items out of which 6 are definitely from the same type of mineral.
Question 15 
You are told that n = 110179 is the product of two primes p and q. The number of
positive integers . less than n that are relatively prime to n (i.e. those m such that
gcd(m, n) = 1) is 109480. What is the value of p + q.
700  
750  
600  
650 
Question 15 Explanation:
We use the concept of Euler to find function. It is used to give the no. of numbers which are less than and relatively prime to n and is represented as, Q(n).
So, ATQ,
n = p = q = 110179 (1)
and Q(n) = (p1)(q1) = 109480 (2)
Now let’s solve (2),
pq  p  q + 1 = 109480
Let put value of pq from (1),
110179  p  q + 1 = 109480
110180  109480 = p + q
Therefore p+q = 700
So, ATQ,
n = p = q = 110179 (1)
and Q(n) = (p1)(q1) = 109480 (2)
Now let’s solve (2),
pq  p  q + 1 = 109480
Let put value of pq from (1),
110179  p  q + 1 = 109480
110180  109480 = p + q
Therefore p+q = 700
Question 16 
The format for car number plates in a country is two digits followed by three vowels,
e.g. 04 IOU. A license plate is called "confusing" if the digit 0 (zero) and the vowel
o are both present on it. For example 04 IOU is confusing but 20 AEI is not. How
are many distinct number plates possible that are not confusing?
12500  
6400  
11341  
None of these 
Question 16 Explanation:
10^{2} × 4^{3} plates without vowel O + 9^{2} × (5^{3} − 4^{3 }) plates with vowel O but without 0. This gives 6400 + 4941 = 11341.
Question 17 
If the letters of the word "PROTECTION" which are at odd numbered position in
English alphabet is picked up and arranged in alphabetical order from the left. If
they are now substituted by Z, Y, X and so on beginning from left, which letter
gets substituted by X?
E  
0  
T  
I 
Question 17 Explanation:
Consider the position of the alphabets A is 1, B is 2, C is 3 and so on then
PROJECTION word gets the following numbers
P is 16, R is 18, O is15, T is 20, E is 5, C is 3, T is 20, I is 9, O is 15, N is 14
The letters O,E,C,I,O are in the odd positions 15,5,3 and 15 respectively
After arranging that letter alphabetical order ,C,E,I,O,O
Now substitute the above letters by Z,Y,X and so on then X will come in place of I.
PROJECTION word gets the following numbers
P is 16, R is 18, O is15, T is 20, E is 5, C is 3, T is 20, I is 9, O is 15, N is 14
The letters O,E,C,I,O are in the odd positions 15,5,3 and 15 respectively
After arranging that letter alphabetical order ,C,E,I,O,O
Now substitute the above letters by Z,Y,X and so on then X will come in place of I.
Question 18 
Shankar ranks 7th from the top in a class of 35 students. What is the rank of Gopal
from bottom who is four ranks below Shankar from top?
25  
26  
27  
28 
Question 18 Explanation:
According to the question rank of gopal from top is 7+4=11. Hence rank of gopal from bottom is 3511+1 =25.
Question 19 
Questions 19 and 20 are based on the following information: P and Q are brothers of R. Q is son of Sand T. S is daughter of U. A is fatherinlaw of T. B is son of U.
What is the relation of P to B?
Nephew  
Paternal uncle  
Niece  
Paternal aunt 
Question 19 Explanation:
P and Q are brothers. Q is son of S and T. S is daughter of U and B is son of U,means B is brother of S.Hence son of S will be nephew of B.Hence P is nephew of B.
Question 20 
Questions 19 and 20 are based on the following information: P and Q are brothers of R. Q is son of Sand T. S is daughter of U. A is fatherinlaw of T. B is son of U.
What is the relation of P to A?
Grandson  
Son  
Daughter  
Father 
Question 20 Explanation:
S is daughter of U and A is fatherinlaw of T,and S and T are couples.Hence we can say that T is father of S and U is mother of S.Now P is son of S ,So P is grandson of A.
Question 21 
Let there be N independent variables Xl, X2, Xs, ... , XN and a dependent variable
y. Suppose we are applying linear regression by fitting the best fit line using least
square error on this data. We find that the coefficient of correlation between y and
one of the variables Xs is 0.95. Which of the following is true for xs?
Relation between Xa and y is weak  
Relation between Xa and y is strong  
Relation between Xs and y is neutral  
It is not possible to judge the relationship 
Question 22 
In one year, three awards (research, teaching and service) will be given to a class
of 25 graduate students in a Statistics Department. If each student can receive at
most one award, how many possible selections are there?
18,800  
13,800  
12,800  
14,800 
Question 22 Explanation:
The correct answer is that we will select 3 students out of 25 students and give awards one to each three of them.Also after selecting three students, the three awards can be distributed in 3! ways. So the correct answer is C(25,3)*3! =13800.
Question 23 
Suppose we are given two variables VI and V2. It is observed from the data that
I. If VI increases then V2 also increases ~
II. If VI decreases then V2'S behaviour is unknown
Which of the following is appropriate for the statistical relationship between VI and V2
Pearson correlation coefficient will be close to 1  
Pearson correlation coefficient will be close to 1  
The data has zero mean and unit variance  
None of the above 
Question 24 
The distribution of students at Harvard University for the professional courses is given in Table 1. Answer questions 2428 based on the data provided in this table.
If 60% of boys and 70% of girls are successful in the courses taken by them, then what is the approximate combined pass percentage?
67.2  
64.1  
62  
68.5 
Question 24 Explanation:
Total no. fo girls = 25 + 23 + 25 + 12 + 25 + 20 + 12 + 3 = 145
Out of which 70% of them passed. So, no. of girls which passed is
≅ 145 × 0.7 ≅ 101
Total no. of boys = 45 + 186 + 120 + 100 + 65 + 32 + 58 + 5 = 611
Out of which 60% of them passed.
So, no. of boys which passed is,
≅ 0.6 × 611 ≅ 366
Combined pass percentage
= 467/756 × 100
= 61.77
≅ 62%
Out of which 70% of them passed. So, no. of girls which passed is
≅ 145 × 0.7 ≅ 101
Total no. of boys = 45 + 186 + 120 + 100 + 65 + 32 + 58 + 5 = 611
Out of which 60% of them passed.
So, no. of boys which passed is,
≅ 0.6 × 611 ≅ 366
Combined pass percentage
= 467/756 × 100
= 61.77
≅ 62%
Question 25 
The distribution of students at Harvard University for the professional courses is given in Table 1. Answer questions 2428 based on the data provided in this table.
Which course has the highest percentage of girls with respect to total number of students enrolled in that course?
Business Management  
Finance  
Computers  
Others 
Question 25 Explanation:
For Business management,
% of girls enrolled = 50/160 × 100 = 31.25
For computers,
% of girls enrolled = 43/261 × 100 = 16.2
For Finance,
% of girls enrolled = 37/215 × 100 = 17.2
For others,
% of girls enrolled = 15/120 × 100 = 12.5
∴ Business management has the highest percentage of girls with respect to total number of students enrolled in that course.
% of girls enrolled = 50/160 × 100 = 31.25
For computers,
% of girls enrolled = 43/261 × 100 = 16.2
For Finance,
% of girls enrolled = 37/215 × 100 = 17.2
For others,
% of girls enrolled = 15/120 × 100 = 12.5
∴ Business management has the highest percentage of girls with respect to total number of students enrolled in that course.
Question 26 
The distribution of students at Harvard University for the professional courses is given in Table 1. Answer questions 2428 based on the data provided in this table.
The percentage of girl engineers doing Business Management is approximately
15%  
40%  
30%  
25% 
Question 26 Explanation:
No. of total students in Business management is, 160.
Out of which no. of girl engineers is, 25.
Hence the required percentage is, (25/160 ) x 100 ≅ 15
Out of which no. of girl engineers is, 25.
Hence the required percentage is, (25/160 ) x 100 ≅ 15
Question 27 
The distribution of students at Harvard University for the professional courses is given in Table 1. Answer questions 2428 based on the data provided in this table.
By what percentage is the number of students doing Computers more than the number of students doing Business Management?
67.2  
63.1  
62  
68.5 
Question 27 Explanation:
No. of students doing computer course = 261
No. of students doing business management course = 160
Hence the required percentage
=(261160)/160=(101/160)x100=63.1%
No. of students doing business management course = 160
Hence the required percentage
=(261160)/160=(101/160)x100=63.1%
Question 28 
The distribution of students at Harvard University for the professional courses is given in Table 1. Answer questions 2428 based on the data provided in this table.
Taking all courses together, by what percentage does the number of boys exceed the number of girls?
521.4%  
231.4%  
321.4%  
421.4% 
Question 28 Explanation:
Total no. of boys = 45 + 186 + 120 + 100 + 65 + 32 + 58 + 5 = 611
Total no. of girls = 25 + 23 + 25 + 12 + 25 + 20 + 12 + 3 = 145
Hence the required percentages is,
611145/145 ≅ 321.4%
Total no. of girls = 25 + 23 + 25 + 12 + 25 + 20 + 12 + 3 = 145
Hence the required percentages is,
611145/145 ≅ 321.4%
Question 29 
Read the following passage and answer questions 2933:
We are always being urged to stay safe online. But in an era where the internet is part of our everyday lives  for work, fun, study, shopping, even managing finances _ it's not always easy to spot the dangers. Web safety expert, Amanda Knox, explores some of the issues lurking in cyberspace.
Her first piece of advice is to install software and a firewall to protect your computer from viruses, hackers and criminals who want to steal your data' qr financial information. "Think of these as your first line of defence," says Amanda. So much for protecting yourself against intruders, but what about other problems? Say you've accidentally deleted an important file or you've been at the mercy of a natural disaster. Katy Marsh runs an online photography business from home and when a fire destroyed part of her house it could easily have spelled ruin for her business too. "Luckily I keep a regular backup of my data so it wasn't a catastrophe." Amanda advises that while backups are good to have we must ensure we protect our computers to start with.
Whilst most of us are aware of the need to protect our computers, it seems we're more lax when it comes to looking out for ourselves, at least according to a recent web awareness survey. Web safety specialists say better personal awareness is needed and this is due in part to the rise of 'Social Networking' sites like 'Facebook' or 'Twitter', which allow us to connect with people around the world with similar interests and professional backgrounds. Chris Simpson, a computer programmer, learnt the hard way. "I joined a free online networking group in the hope of making some professional contacts to help me find a new job. After a month, one of my online contacts invited me to take out a subscription to a club that prom)sed access to a network of job recruiters. It turned out to be a waste of money. I ended up a laughing stock with my mates  they couldn't believe that someone in my job could get taken in so easily." No wonder then that Amanda warns, "It's easy to get complacent and let our guard down when we meet someone with the same interests online. "
This brings us to other potential pitfalls. Are the people you meet online who they really claim to be? Can you be sure the person you're chatting with is in fact a 22 yearold Maths undergraduate from London and not someone merely masquerading as a student to win your trust?
When networking and joining online communities it's better to be cautious about the amount of personal information you share. For example, it isn't always necessary to use your real name as a username when registering for a service. You could instead use a pseudonym, or a name that doesn't give away your real identity to other users. And is it really important to tell the world details about your school, college or any local clubs you're a member of? Sometimes it pays to be a little vague and simply say something like 'I'm studying at college in Madrid at the moment and I'm a member of a local tennis club '.
If you do experience problems from another user, be prepared to report them for misusing the service. You'll be doing other users a favour too. And if all else fails, check to see if it is easy to delete your account and leave the service if you choose to and that you have the option to delete all your details. A general rule of thumb is not to post any information about yourself that you would not be happy for the sSworld to know  not just now but in years to come. It's not always easy to remove . information after it's been posted so you  not to mention your future employer  may have an unpleasant surprise a few years down the line.
In the second paragraph the phrase 'first line of defence' refers to
taking regular backup  
use protections.  
disconnecting the internet.  
showing weakness. 
Question 29 Explanation:
First line of defence means defensive structure consisting of a barrier that can be employed for defense against attack.Hence option B is most appropriate answer.
Question 30 
Read the following passage and answer questions 2933:
We are always being urged to stay safe online. But in an era where the internet is part of our everyday lives  for work, fun, study, shopping, even managing finances _ it's not always easy to spot the dangers. Web safety expert, Amanda Knox, explores some of the issues lurking in cyberspace.
Her first piece of advice is to install software and a firewall to protect your computer from viruses, hackers and criminals who want to steal your data' qr financial information. "Think of these as your first line of defence," says Amanda. So much for protecting yourself against intruders, but what about other problems? Say you've accidentally deleted an important file or you've been at the mercy of a natural disaster. Katy Marsh runs an online photography business from home and when a fire destroyed part of her house it could easily have spelled ruin for her business too. "Luckily I keep a regular backup of my data so it wasn't a catastrophe." Amanda advises that while backups are good to have we must ensure we protect our computers to start with.
Whilst most of us are aware of the need to protect our computers, it seems we're more lax when it comes to looking out for ourselves, at least according to a recent web awareness survey. Web safety specialists say better personal awareness is needed and this is due in part to the rise of 'Social Networking' sites like 'Facebook' or 'Twitter', which allow us to connect with people around the world with similar interests and professional backgrounds. Chris Simpson, a computer programmer, learnt the hard way. "I joined a free online networking group in the hope of making some professional contacts to help me find a new job. After a month, one of my online contacts invited me to take out a subscription to a club that prom)sed access to a network of job recruiters. It turned out to be a waste of money. I ended up a laughing stock with my mates  they couldn't believe that someone in my job could get taken in so easily." No wonder then that Amanda warns, "It's easy to get complacent and let our guard down when we meet someone with the same interests online. "
This brings us to other potential pitfalls. Are the people you meet online who they really claim to be? Can you be sure the person you're chatting with is in fact a 22 yearold Maths undergraduate from London and not someone merely masquerading as a student to win your trust?
When networking and joining online communities it's better to be cautious about the amount of personal information you share. For example, it isn't always necessary to use your real name as a username when registering for a service. You could instead use a pseudonym, or a name that doesn't give away your real identity to other users. And is it really important to tell the world details about your school, college or any local clubs you're a member of? Sometimes it pays to be a little vague and simply say something like 'I'm studying at college in Madrid at the moment and I'm a member of a local tennis club '.
If you do experience problems from another user, be prepared to report them for misusing the service. You'll be doing other users a favour too. And if all else fails, check to see if it is easy to delete your account and leave the service if you choose to and that you have the option to delete all your details. A general rule of thumb is not to post any information about yourself that you would not be happy for the sSworld to know  not just now but in years to come. It's not always easy to remove . information after it's been posted so you  not to mention your future employer  may have an unpleasant surprise a few years down the line.
The effect of the fire was
worse for Katy's business than her home.  
to ruin Katy's business.  
not as serious for Katy's business as it could have been.  
to make Katy start to back up her data. 
Question 30 Explanation:
From the line "Luckily I keep a regular backup of my data so it wasn't a catastrophe." it is clear that loss was not as much as it could have been.
Question 31 
Read the following passage and answer questions 2933:
We are always being urged to stay safe online. But in an era where the internet is part of our everyday lives  for work, fun, study, shopping, even managing finances _ it's not always easy to spot the dangers. Web safety expert, Amanda Knox, explores some of the issues lurking in cyberspace.
Her first piece of advice is to install software and a firewall to protect your computer from viruses, hackers and criminals who want to steal your data' qr financial information. "Think of these as your first line of defence," says Amanda. So much for protecting yourself against intruders, but what about other problems? Say you've accidentally deleted an important file or you've been at the mercy of a natural disaster. Katy Marsh runs an online photography business from home and when a fire destroyed part of her house it could easily have spelled ruin for her business too. "Luckily I keep a regular backup of my data so it wasn't a catastrophe." Amanda advises that while backups are good to have we must ensure we protect our computers to start with.
Whilst most of us are aware of the need to protect our computers, it seems we're more lax when it comes to looking out for ourselves, at least according to a recent web awareness survey. Web safety specialists say better personal awareness is needed and this is due in part to the rise of 'Social Networking' sites like 'Facebook' or 'Twitter', which allow us to connect with people around the world with similar interests and professional backgrounds. Chris Simpson, a computer programmer, learnt the hard way. "I joined a free online networking group in the hope of making some professional contacts to help me find a new job. After a month, one of my online contacts invited me to take out a subscription to a club that prom)sed access to a network of job recruiters. It turned out to be a waste of money. I ended up a laughing stock with my mates  they couldn't believe that someone in my job could get taken in so easily." No wonder then that Amanda warns, "It's easy to get complacent and let our guard down when we meet someone with the same interests online. "
This brings us to other potential pitfalls. Are the people you meet online who they really claim to be? Can you be sure the person you're chatting with is in fact a 22 yearold Maths undergraduate from London and not someone merely masquerading as a student to win your trust?
When networking and joining online communities it's better to be cautious about the amount of personal information you share. For example, it isn't always necessary to use your real name as a username when registering for a service. You could instead use a pseudonym, or a name that doesn't give away your real identity to other users. And is it really important to tell the world details about your school, college or any local clubs you're a member of? Sometimes it pays to be a little vague and simply say something like 'I'm studying at college in Madrid at the moment and I'm a member of a local tennis club '.
If you do experience problems from another user, be prepared to report them for misusing the service. You'll be doing other users a favour too. And if all else fails, check to see if it is easy to delete your account and leave the service if you choose to and that you have the option to delete all your details. A general rule of thumb is not to post any information about yourself that you would not be happy for the sSworld to know  not just now but in years to come. It's not always easy to remove . information after it's been posted so you  not to mention your future employer  may have an unpleasant surprise a few years down the line.
According to the web awareness survey, our attitude to our personal safety is rather
relaxed  
concerned  
positive.  
uncertain 
Question 32 
Read the following passage and answer questions 2933:
We are always being urged to stay safe online. But in an era where the internet is part of our everyday lives  for work, fun, study, shopping, even managing finances _ it's not always easy to spot the dangers. Web safety expert, Amanda Knox, explores some of the issues lurking in cyberspace.
Her first piece of advice is to install software and a firewall to protect your computer from viruses, hackers and criminals who want to steal your data' qr financial information. "Think of these as your first line of defence," says Amanda. So much for protecting yourself against intruders, but what about other problems? Say you've accidentally deleted an important file or you've been at the mercy of a natural disaster. Katy Marsh runs an online photography business from home and when a fire destroyed part of her house it could easily have spelled ruin for her business too. "Luckily I keep a regular backup of my data so it wasn't a catastrophe." Amanda advises that while backups are good to have we must ensure we protect our computers to start with.
Whilst most of us are aware of the need to protect our computers, it seems we're more lax when it comes to looking out for ourselves, at least according to a recent web awareness survey. Web safety specialists say better personal awareness is needed and this is due in part to the rise of 'Social Networking' sites like 'Facebook' or 'Twitter', which allow us to connect with people around the world with similar interests and professional backgrounds. Chris Simpson, a computer programmer, learnt the hard way. "I joined a free online networking group in the hope of making some professional contacts to help me find a new job. After a month, one of my online contacts invited me to take out a subscription to a club that prom)sed access to a network of job recruiters. It turned out to be a waste of money. I ended up a laughing stock with my mates  they couldn't believe that someone in my job could get taken in so easily." No wonder then that Amanda warns, "It's easy to get complacent and let our guard down when we meet someone with the same interests online. "
This brings us to other potential pitfalls. Are the people you meet online who they really claim to be? Can you be sure the person you're chatting with is in fact a 22 yearold Maths undergraduate from London and not someone merely masquerading as a student to win your trust?
When networking and joining online communities it's better to be cautious about the amount of personal information you share. For example, it isn't always necessary to use your real name as a username when registering for a service. You could instead use a pseudonym, or a name that doesn't give away your real identity to other users. And is it really important to tell the world details about your school, college or any local clubs you're a member of? Sometimes it pays to be a little vague and simply say something like 'I'm studying at college in Madrid at the moment and I'm a member of a local tennis club '.
If you do experience problems from another user, be prepared to report them for misusing the service. You'll be doing other users a favour too. And if all else fails, check to see if it is easy to delete your account and leave the service if you choose to and that you have the option to delete all your details. A general rule of thumb is not to post any information about yourself that you would not be happy for the sSworld to know  not just now but in years to come. It's not always easy to remove . information after it's been posted so you  not to mention your future employer  may have an unpleasant surprise a few years down the line.
What tip does the writer give for joining an online community?
always use a false name.  
make sure you are properly registered.  
limit the information you give to others.  
tell other users where you're stUdying 
Question 32 Explanation:
The that the writer gave for joining an online community is that we should give limited personal information to other
Question 33 
Read the following passage and answer questions 2933:
We are always being urged to stay safe online. But in an era where the internet is part of our everyday lives  for work, fun, study, shopping, even managing finances _ it's not always easy to spot the dangers. Web safety expert, Amanda Knox, explores some of the issues lurking in cyberspace.
Her first piece of advice is to install software and a firewall to protect your computer from viruses, hackers and criminals who want to steal your data' qr financial information. "Think of these as your first line of defence," says Amanda. So much for protecting yourself against intruders, but what about other problems? Say you've accidentally deleted an important file or you've been at the mercy of a natural disaster. Katy Marsh runs an online photography business from home and when a fire destroyed part of her house it could easily have spelled ruin for her business too. "Luckily I keep a regular backup of my data so it wasn't a catastrophe." Amanda advises that while backups are good to have we must ensure we protect our computers to start with.
Whilst most of us are aware of the need to protect our computers, it seems we're more lax when it comes to looking out for ourselves, at least according to a recent web awareness survey. Web safety specialists say better personal awareness is needed and this is due in part to the rise of 'Social Networking' sites like 'Facebook' or 'Twitter', which allow us to connect with people around the world with similar interests and professional backgrounds. Chris Simpson, a computer programmer, learnt the hard way. "I joined a free online networking group in the hope of making some professional contacts to help me find a new job. After a month, one of my online contacts invited me to take out a subscription to a club that prom)sed access to a network of job recruiters. It turned out to be a waste of money. I ended up a laughing stock with my mates  they couldn't believe that someone in my job could get taken in so easily." No wonder then that Amanda warns, "It's easy to get complacent and let our guard down when we meet someone with the same interests online. "
This brings us to other potential pitfalls. Are the people you meet online who they really claim to be? Can you be sure the person you're chatting with is in fact a 22 yearold Maths undergraduate from London and not someone merely masquerading as a student to win your trust?
When networking and joining online communities it's better to be cautious about the amount of personal information you share. For example, it isn't always necessary to use your real name as a username when registering for a service. You could instead use a pseudonym, or a name that doesn't give away your real identity to other users. And is it really important to tell the world details about your school, college or any local clubs you're a member of? Sometimes it pays to be a little vague and simply say something like 'I'm studying at college in Madrid at the moment and I'm a member of a local tennis club '.
If you do experience problems from another user, be prepared to report them for misusing the service. You'll be doing other users a favour too. And if all else fails, check to see if it is easy to delete your account and leave the service if you choose to and that you have the option to delete all your details. A general rule of thumb is not to post any information about yourself that you would not be happy for the sSworld to know  not just now but in years to come. It's not always easy to remove . information after it's been posted so you  not to mention your future employer  may have an unpleasant surprise a few years down the line.
In the final paragraph, the writer advises people
not to put photos online.  
to apply for a job online.  
to post personal information online.  
to ponder before making personal information public.

Question 33 Explanation:
In the final paragraph the writer advises to think carefully before making personal information public
Question 34 
Questions 34 and 35 are based on the flowchart given in Figure 1
For an individual who works for a government organization and owns a house, it is given that he is 35 years old and earns Rs. 15,000 per month. What would be the approved_amt (in Rs.) for him?
15,00,000  
18,75,000  
16,00,000  
20,50,000 
Question 35 
A person wishes to avail a loan of Rs. 50,00,000. He works for a government organization arid does not own a house. Would he get the loan if he draws a salary of Rs. 60,000 and his age is 28 years? If he does get a loan, what amount would he be entitled? If not, by what amount he would be short of the required amount?
Yes, he would get a loan equal to Rs. 57,60,000.  
Yes, he would get a loan exactly equal to Rs. 50,00,000.  
No, he would not get a loan. He would be short of Rs. 7,00,000.  
No, he would not get a loan. He would be short of Rs. 7,60,000. 
Question 35 Explanation:
From the given chart and following the conditions of the above question, he will get the loan of
60000*3*(60age) =60000*3*32 = 5760000.
Question 36 
In the following two questions (3637), first a statement is presented followed by two conclusions numbered I and II. If the statement is considered true, you may workout whether the conclusions follow logically from the information given in the statement.
Statement: The old order changed yielding place to new.
Conclusion I: Change is law of nature.
Conclusion II: Discard old ideas because they are old.
Which of the following is true?
Only conclusion I follows  
Only conclusion II follows  
Both I and II follow  
None of the above

Question 36 Explanation:
Only conclusion I follows
Question 37 
In the following two questions (3637), first a statement is presented followed by two conclusions numbered I and II. If the statement is considered true, you may workout whether the conclusions follow logically from the information given in the statement.
Statement: Government has spoiled many top ranking financial institutions appointing bureaucrats as directors of these institutions.
Conclusion I: Government should appoint directors of the financial institutes taking into consideration the expertise of the person in the area of finance.
Conclusion II: The director of the financial institute should have expertise commensurate with the financial work carriedout by the institute.
Which of the· following is true ?
Neither I nor II follows  
Only conclusion I follows  
Only conclusion II follows
 
Both I and II follow 
Question 37 Explanation:
Both conclusions are true w.r.to given statement
Question 38 
Give the negation of the following statement:
For some n, for every word w in the dictionary L, w has at least n meanings.
For some n, there is a word w in the dictionary L, w has at least n meanings  
For some n, there is at least one word w in the dictionary L, w has at most n
meanings.
 
Given any n, all the words w in the dictionary L have at most n meanings.  
Given any n, there is at least one word w in the dictionary L that has at most
n meanings.
 
None of the given options is correct. 
Question 38 Explanation:
Question 39 
Suppose time for execution taken by algorithms A and B are written as t(A) and
t(B) respectively. If the algorithm A performs exponentially faster than an algorithm
B then,
The time taken by A is greater than the time taken by B  
Time taken by A is exp(t(B))  
Time taken by A is log(t(B))  
None of the above 
Question 40 
A machine uses a 16bit two's complement representation for integers, and little endian byteordering, this means that the least significant byte of an integer is stored at the lower address. What is the output for the following program fragment?
int x; /* 16 bit signed integer */
char *p = (char *) & x;
x = 0x0013;
printf(“x=%d \n" ,x);
printf("%d %d\n", p[0],p[1]);
x=9 19 0  
x=19 9 0  
x=9 9 0  
None of the above

Question 40 Explanation:
Pointer p points to variable x.
The value assigned to the x is 0x0013 which is in hexadecimal form whose decimal value is 19.
So “printf(“x=%d \n" ,x);” will print 19
. Now since p points to variable x so p[0] will print the same value present in x,i.e., 19 and p[1] ponts to nowhere due to which it will print 0
Therefore the output will be,
x=19
19 0
The value assigned to the x is 0x0013 which is in hexadecimal form whose decimal value is 19.
So “printf(“x=%d \n" ,x);” will print 19
. Now since p points to variable x so p[0] will print the same value present in x,i.e., 19 and p[1] ponts to nowhere due to which it will print 0
Therefore the output will be,
x=19
19 0
Question 41 
A 64kB direct mapped cache has 16 byte blocks. If the address is of 32 bit, how
many bits are used for tag, index and offset in this cache?
16,13,4
 
12,16,4  
16,12,4  
16,14,4 
Question 41 Explanation:
For offset bits, Block size = 16 byte = 2^{4} byte
So, offset bits = 4
For index bits,
Cache size/Block size = No. of blocks = 2^{16}/2^{4} = 2^{12}
So, index bits = 12
Now tag bits,
32  (offset bits + index bits)
= 32  (4 + 12)
= 16
Question 42 
A nonpipeline system takes 40ns to process a task. The same task can be processed
in a 6segment pipeline with a clock cycle of 10ns. Determine the speed up ratio of
the pipeline for 100 tasks.
4.8  
5.1  
4.76  
4.92  
None of the given option is correct. 
Question 42 Explanation:
Now tag bits,
32  (offset bits + index bits)
= 32  (4 + 12)
= 16
Time taken without pipeline to complete 100 tasks,
100 × 40ns = 4000 ns
Time taken with pipeline to complete 100 tasks,
1 × 6 × 10ns + 99 × 1 × 10ns
= 60 + 990
= 1050 ns
∴ Speedup ratio = 4000ns/1050ns = 3.8
32  (offset bits + index bits)
= 32  (4 + 12)
= 16
Time taken without pipeline to complete 100 tasks,
100 × 40ns = 4000 ns
Time taken with pipeline to complete 100 tasks,
1 × 6 × 10ns + 99 × 1 × 10ns
= 60 + 990
= 1050 ns
∴ Speedup ratio = 4000ns/1050ns = 3.8
Question 43 
Consider an instruction pipeline with five stages without any branch prediction.
Fetch Instruction(FI), Decode Instruction(DI), Fetch Operand(FO), Execute Instruction(
EI) and Write Operand(WO). The stage delays for FI, DI, FO, EI and
WO are 5 ns, 7 ns, 10 ns, 8 ns and 6 ns, respectively. There are intermediate storage
buffers after each stage and the delay of each buffer is 1 ns. A program consisting
of 12 instructions I_{1}, I_{2}, I_{3} , ••• ,I_{12} is executed in this instruction pipeline, the time
(in ns) needed to complete the program is
132  
165  
176  
32 
Question 43 Explanation:
Cycle time = maximum stage delay out of given five stage delay + buffer delay
= 10ns + 1ns
= 11ns
First instruction will take five cycles and then the remaining instruction will take 1 cycle to complete their execution.
So, total cycle required to complete the execution of i.e., instruction is
1 × 5 + 11 × 1 = 16
Hence total execution time
= No. of cycles × cycle time
= 16 × 11 ns
= 176 ns
= 10ns + 1ns
= 11ns
First instruction will take five cycles and then the remaining instruction will take 1 cycle to complete their execution.
So, total cycle required to complete the execution of i.e., instruction is
1 × 5 + 11 × 1 = 16
Hence total execution time
= No. of cycles × cycle time
= 16 × 11 ns
= 176 ns
Question 44 
While implementing a priority queue, the minimum number of queues required is?
one  
two  
three  
four 
Question 44 Explanation:
Priority queues are applied using a 2D array where it has two rows one for element and second for priority ,so minimum numbers of queues are needed to implement two.
Question 45 
A binary search tree where the difference between the heights of the left subtree
and the right subtree can never be more than one is known as
RedBlack tree
 
Lemma tree  
AVL Tree  
Spanning Tree 
Question 45 Explanation:
AVL tree is a binary search tree in which the difference of heights of left and right subtrees of any node is less than or equal to one.
Question 46 
What is the value of the variable var after executing the following lines of C code assuming variables of type int are represented using 4 bytes .
int var = 1;
while(var >= 1)
{
var = var + 1;
}
2^{31} 1  
2^{31}  
Program goes to infinite loop  
2^{31} 1  
None of the above

Question 46 Explanation:
Since by default the int data type is signed so the maximum value that var can contain is 2^31 1.
After that if again 1 is added to var then the value of var will become 0 (because the value of var will become 2^31 which needs at least 33 bit to store it but int data type has only 32 bit) and then loop will get terminated since 0 is not >= 1 .Hence the final value of var after complete execution will be 0.
After that if again 1 is added to var then the value of var will become 0 (because the value of var will become 2^31 which needs at least 33 bit to store it but int data type has only 32 bit) and then loop will get terminated since 0 is not >= 1 .Hence the final value of var after complete execution will be 0.
Question 47 
Which of the following is the correct order of operator evaluation for the expression:
i + 5  x < ! i && z
+, , <, !, &&  
!, + , <, , &&  
!, +, <, &&, 
 
!, +,, <, && 
Question 47 Explanation:
The correct precedence order will be
Unary operator > arithmetic operator > comparison operator > Logical AND >logical OR
So finally the answer will be ,
! , +, < ,&& , 
Unary operator > arithmetic operator > comparison operator > Logical AND >logical OR
So finally the answer will be ,
! , +, < ,&& , 
Question 48 
An unsorted array containing n elements has the property that every element in
the array is at most k distance" from its position in the sorted array, where k is
a positive integer smaller than n. What is the best time complexity to sort this
array?
O(nk)
 
O(n log k)  
O(n^{2})  
O(n log log k) 
Question 48 Explanation:
The Min Heap based method takes O(nLogk) time and uses O(k) auxiliary space.
Question 49 
What is the solution of the recurrence T(n) = T(n/4) + T(n/2) + cn^{2}
O(n^{3})  
O(n^{2})  
O(n^{2} log n)  
O(n^{3} log n) 
Question 49 Explanation:
Question 50 
The number of paths of length 3 between two different vertices in K_{4} is
7  
6  
9  
8 
Question 50 Explanation:
Question 51 
A word that does NOT get accepted by the Regular Expression (01^{*} + 10)^{*} is
00  
11  
100  
1001 
Question 51 Explanation:
whatever string is generated by given regular expression ,it must contain atleast one 0, but option B do not have any 0.So string in option B cannot be generated.
Question 52 
The adjacency matrix of the following graph is:
All of the above 
Question 52 Explanation:
Adjacency matrix for the given graph is
Question 53 
What is true for the following graphs
(i) is planar but (ii) is not
 
Both are planar
 
(ii) is planar but (i) is not  
Both are not planar 
Question 53 Explanation:
Let’s check for graph 1st,
Yes, it is planar. Let's check for graph 2nd,
Yes, it is also planar.
Yes, it is planar. Let's check for graph 2nd,
Yes, it is also planar.
Question 54 
Number of states required by a minimal Deterministic Finite Automata (DFA) that
recognizes the language a*b is
2  
3  
1  
4 
Question 54 Explanation:
Question 55 
What is the language of the following grammar
S→ 0S1  1S0  ε
S→ 0S1  1S0  ε
{w: w has equal number of 0's and 1's }  
{0^{n}1^{n} U 1^{n}0^{n} : n ≥ 0}  
Words having equal number of 0's and 1 's whose start and end symbols are not the same  
Words having equal number of 0's and 1's whose start and end symbols are the same 
Question 55 Explanation:
The given grammar generates the strings which have equal no. of 0’s and 1’s whose start and end symbols are not the same.
Question 56 
Indicate a set of words that does NOT get generated by the following grammar
S→ aSb  bY Ya
Y→ bY  aY  ε
S→ aSb  bY Ya
Y→ bY  aY  ε
{a^{n}b^{n} : n ≥ 1}  
{a^{n}b^{n1} : n ≥ 1}  
{a^{n+1}b^{n} : n ≥ 1}  
{a^{n}bab^{n} : n ≥1} 
Question 56 Explanation:
The language in option A is not generated by given grammar.
Question 57 
The problem of finding if two regular languages have at least one string in common
is
decidable  
Recursively enumerable (RE), but not recursive  
nonRE  
None of the above 
Question 57 Explanation:
There are only four cases in which regular languages are not closed
1)Infinite union
2)Infinite intersection
3)Superset
4)Subset
1)Infinite union
2)Infinite intersection
3)Superset
4)Subset
Question 58 
Let L = {a^{n}b^{n} : 0 ≤ n ≤ 100}. Then L is
Context free, but ;not regular  
Recursive, but not context free  
Recursively enumerable, but not recursive  
Regular 
Question 58 Explanation:
Since the value of n is finite and every finite language is regular. Hence the given language is regular language.
Question 59 
What is the time complexity to find a simple cycle in a graph of n vertices?
O(n^{2})  
O(n)  
O(n log n)
 
O(n^{n})

Question 59 Explanation:
We can use DFS to find the cycle in the graph of n vertices and its time complexity is O(E+n).
But since it is not given in the option ,so the best choice will be O(n^2).
Question 60 
What is the output of the function fun when head points to the first node of the following linked list?
2> 4 > 6> 8> 2 > 4
void fun(struct node* head)
{
if(head == NULL)
return;
printf ("%d ", head>data);
if(head>next != NULL)
fun(head>next>next);
printf("%d ", head>data);
}
284482  
268  
262262  
None of the above 
Question 60 Explanation:
The given function prints the alternate no.s from start and then prints the same in reverse.
So the answer will be 262262.
Question 61 
Which of the following scheduling algorithms do NOT lead to starvation:
I. FCFS
II. SJF
III. Round Robin
IV. Priority Scheduling
I, II, III  
I, III  
I, II  
I, III, IV

Question 61 Explanation:
In FCFS and Round robin first come first serve is applied so no starvation. But in the SJF the process may starve because the job with the longest burst time may starve if the process with shortest burst time keep coming,and in priority scheduling also the low priority process may starve if the high priority process keep coming.
Question 62 
Which of following binding schemes has loss of efficiency if there is no TLB in the
system?
Compiletime binding  
Loadtime binding
 
Runtime binding  
None of the above 
Question 62 Explanation:
Address binding of instructions and data to memory addresses can happen at three different stages
Compile time: If memory location known a priori, absolute code can be generated; must recompile code if starting location changes
Load time: Must generate relocatable code if memory location is not known at compile time
Execution time: Binding delayed until run time if the process can be moved during its execution from one memory segment to another
The user program deals with logical addresses; it never sees the real physical addresses
Executiontime binding occurs when reference is made to location in memory
Logical address bound to physical addresses
Compile time: If memory location known a priori, absolute code can be generated; must recompile code if starting location changes
Load time: Must generate relocatable code if memory location is not known at compile time
Execution time: Binding delayed until run time if the process can be moved during its execution from one memory segment to another
The user program deals with logical addresses; it never sees the real physical addresses
Executiontime binding occurs when reference is made to location in memory
Logical address bound to physical addresses
Question 63 
A file system has 32 disk blocks overall. It maintains its free disk blocks as a bit
vector. Currently, the bit vector is 00001100 11111100 00000000 00110000. When
a file is created with a certain number of blocks the free blocks are always allocated
from the least numbered block (the leftmost bit in the bit vector). The file system
uses noncontiguous file allocation scheme. When a file with a requirement of 10
blocks is created the new bit vector will be:
00001100 11111100 11111111 11110000  
00111111 11111111 11111111 11111111  
11111111 11111111 11111111 11111100
 
None of the above

Question 64 
The number of page table entries for a 64bit processor with 16KB page size is,
2^{50}  
2^{51}  
2^{18}  
2^{64} 
Question 64 Explanation:
No. of page table entries is,
(2^{64})/(2^{14})=2^{50}
(2^{64})/(2^{14})=2^{50}
Question 65 
In which of the following Multithreading techniques will the process be blocked if
one of the threads blocks?
Onetoone Multithreading  
Manytoone Multithreading  
Manytomany Multithreading  
N one of the above

Question 65 Explanation:
In many to one multithreading the whole process will get blocked if one of the threads gets blocked because every thread is attached to only one kernel.And kernels do not differentiate between user level threads.
Question 66 
Which of the following conditions leads to thrashing? (WSS is Working Set Size)
All processes are allocated more memory than their WSS  
The sum of the WSS of the processes is less than the main memory  
One of the processes is allocated more memory than its WSS  
The sum of the WSS of the processes is more than the main memory

Question 66 Explanation:
Thrashing is a condition in which excessive page fault operations are taking place. A system that is thrashing can be perceived as either a very slow system or one that has come to a halt. If the WSS of processes is more than the main memory then there will be always page fault because the required no. of frames is not there in the main memory.
Question 67 
TTL field in IP header is used for the following purpose:
To determine if the network is congested  
To drop a packet that may be in a routing loop  
To detect errors in the IP packet during transmission
 
To slow down traffic from a fast sender

Question 67 Explanation:
TTL is used to prevent the packet from getting into infinite loop.
Question 68 
If a class B network is subnetted such that there are at least 20 subnets, what is
the minimum number of bits that need to be used for the subnet mask?
4  
8  
3  
5 
Question 68 Explanation:
The minimum no. of bits required for the subnets is base 2 log (20) = 5 bit.
Question 69 
Questions 7273 are based on following information: In the network topology shown in Figure 2, assume that every host (i.e., A, B, C and D) have default router as the router to its right if it has more than one router connected to it, i.e., for Band C, it is R2 and R3 respectively. Otherwise, the default router is the router connected to it. Also, assume that all the networks shown in the figure have default network masks as per their class and that all routers have entries for all the networks shown in the figure. The routers do NOT have default routes nor for any networks not shown in·the figure. The MTUs of the links ate shown on each of the links.
When 10.5.0.91 pings 202.41.85.116, which of the following IOMP messages is sent?
IOMP Network Unreachable Message
 
IOMP Host Unreachable Message  
IOMP Time Exceeded  
IOMP Redirect 
Question 70 
Questions 7273 are based on following information: In the network topology shown in Figure 2, assume that every host (i.e., A, B, C and D) have default router as the router to its right if it has more than one router connected to it, i.e., for Band C, it is R2 and R3 respectively. Otherwise, the default router is the router connected to it. Also, assume that all the networks shown in the figure have default network masks as per their class and that all routers have entries for all the networks shown in the figure. The routers do NOT have default routes nor for any networks not shown in·the figure. The MTUs of the links ate shown on each of the links.
When 10.5.0.91 pings 202.41.85.117 with TTL=2, which of the following IOMP messages are received in reply?
ICMP Destination Unreachable  
ICMP Time Exceeded
 
ICMP Echo Reply  
ICMP Host Unreachable 
Question 71 
If a TCP client sends segments with sizes 100B, 200B, 500B, 150B and 20B, all
with PSH bit set, which of the following is NOT a possible sequence of TCP acknowledgements
received?
101, 201, 501, 151, 21  
101, 101, 801, 951, 971  
101,301, 801, 801, 971  
101, 101, 101, 951, 971

Question 72 
DHCP protocol is NOT used for which of the following?
Assign IP address  
Discover the default router  
Discover the DNS server
 
Discover the path to the destination 
Question 72 Explanation:
The Dynamic Host Configuration Protocol (DHCP) is a network management protocol used on Internet Protocol networks whereby a DHCP server dynamically assigns an IP address and other network configuration parameters to each device on a network so they can communicate with other IP networks.
A DHCP server enables computers to request IP addresses and networking parameters automatically from the Internet service provider (ISP), reducing the need for a network administrator or a user to manually assign IP addresses to all network devices.
A DHCP server enables computers to request IP addresses and networking parameters automatically from the Internet service provider (ISP), reducing the need for a network administrator or a user to manually assign IP addresses to all network devices.
Question 73 
The maximum number of superkeys for the relation schema R(E,f,G,R) with E as
the key is
8  
7  
5  
6 
Question 73 Explanation:
Since E is the key so it has to be included since we need superkeys. And for the remaining attribute they might be present or they might not be present,So we can say that for the remaining attributes we have two choices .So the answer will be 2*2*2 = 8
Question 74 
Suppose there are three relations as given below:
(a) R(a,b)= (0,1),(4,5),(8,9).
(b) S(b,c )=(1,2),(5,2),(5,6),(5,10),(13,10).
(c) T( c,d)=(2,3),(6,7)(10,1l ),(10,3)
The number of tuples in (R * S) * T, where * is the full natural outer join, is:
5  
8  
13  
60 
Question 74 Explanation:
Question 75 
Consider a relation R(A,B) and primary key is A and B is a foreign key referencing
to A. Which of the following row sequences can be inserted into R.
(a1,a2)(a2,a3) (a3,a4)a4,a5)  
(a1,null) (a2,a1) (a3,a2) (a4,a5)  
(a1,null) (a2,a1)(a4,a3) (a3,a2)  
None of the above can be inserted

Question 75 Explanation:
Let’s check option wise,
A) (a1, a2) can’t be inserted because B is foreign key referencing A and A do not contain a2, so (a1, a2) can’t be inserted.
B) (a1, Null) is inserted.
(a2, a1) is inserted, since a1 is present in A.
(a3, a2) is inserted, since a2 is present in A.
(a4, a5) can’t be inserted because a5 is not present in A.
C) (a1, Null) is inserted.
(a2, a1) is inserted, since a1 is present in A.
(a4, a3) can’t be inserted because a3 is not present in A.
Hence, none of the given sequences can be inserted.
A) (a1, a2) can’t be inserted because B is foreign key referencing A and A do not contain a2, so (a1, a2) can’t be inserted.
B) (a1, Null) is inserted.
(a2, a1) is inserted, since a1 is present in A.
(a3, a2) is inserted, since a2 is present in A.
(a4, a5) can’t be inserted because a5 is not present in A.
C) (a1, Null) is inserted.
(a2, a1) is inserted, since a1 is present in A.
(a4, a3) can’t be inserted because a3 is not present in A.
Hence, none of the given sequences can be inserted.
Question 76 
The following table has two attributes X and Z, where X is the primary key and Z is the foreign key referencing X with ondelete cascade.
The set of all tuples that are additionally deleted to preserve referential integrity when the tuple (2,4) is deleted are:
(3,4) and (6,4)  
(5,2) and (7,2)  
(5,2), (7,2) and (9,5)  
(3,4), (4,3) and (6,4) 
Question 76 Explanation:
The tuple (2,4) is deleted, so all the rows will be deleted in which Z contains value 2. So (5,2), (7,2) will also be deleted.
Now since (5,2) and (7,2) is deleted, so all the rows will be deleted in which Z contains values 5 & 7. So (9,5) will be deleted.
Now since (9,5) is deleted, so all the rows will be deleted in which Z contains 9. But since Z does not contain 9 so here the deletion stops.
Hence the additional deleted rows are (5,2), (7,2), (9,5).
Question 77 
Consider the following tables Tl and T2:
In table Tl, P is the primary key, Q is the foreign key referencing R in table T2
with ondelete cascade and onupdate cascade. In table T2, R is the primary key and S is the foreign key referencing P in the table Tl with ondelete set NULL and onupdate cascade. In order to delete record (3,8) from table, number of additional records that need to be deleted from table T1 is
0  
1  
2  
3 
Question 77 Explanation:
Row (3,8) is deleted from T1 , so in T2 whichever rowS contains 3 will be replaced with null for only S value of that row due to condition “ondelete set NULL” .And no further modification in any of the table is required.
Question 78 
Hundred students answered a question paper that was set for 50 marks. The maximum
mark obtained was 45 and the average of the marks was say a and standard
deviation of this distribution was σ
. Then it was decided to add 5 marks to all the
students and the total marks of the paper was scaled to 100. If a_{new} is the new
average and σ
_{new} is the standard deviation of the modified distribution, then which
of the following is true.
a_{new} = a + 5, σ
_{new} = σ  
a_{new} = 2(a + 5), σ
_{new} =σ  
a_{new} = 2(a + 5), σ
_{new} = 2σ  
a_{new} = a, σ
_{new} = σ 
There are 78 questions to complete.