Computer-Networks

Consider a token ring topology with N stations (numbered 1 to N) running token ring protocol where the stations are equally spaced. When a station gets the token it is allowed to send one frame of fixed size. Ring latency is t_p, while the transmission time of a frame is t_t. All other latencies can be neglected.
The maximum utilization of the token ring when t_t = 5 ms, t_p = 3 ms, N = 15 is: