Question 3400 – Mathematical-Reasoning
December 17, 2023Question 3354 – Mathematical-Reasoning
December 17, 2023Question 3353 – Mathematical-Reasoning
A group of 210 students appeared in some test. The mean of 1/3 rd of students is found to be 60. The mean of the remaining students is found to be 78. The mean of the whole group will be:
Correct Answer: D
Question 40 Explanation:
Given data:
Total number of students = 210
1/3 rd of 210 = 70 students
Mean marks of 70 students = 60
Total number of students = 210
1/3 rd of 210 = 70 students
Mean marks of 70 students = 60
To Find: Mean of the whole group= ?
Let the sum of marks of 70 students be X
Mean = X / Number of students
60 = X/70
X = 70*60
⇒ Sum of marks of 70 students = 4200
Remaining students = 210 – 70 = 140 students
Mean of 140 students = 78
Sum of marks of 78 students = 140*78 = 10920
Total marks of 210 students = 4200 + 10920
= 15120
Mean of whole group = 15120 / 210
= 72 marks
80
76
74
72