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 tp, while the transmission time of a frame is tt. All other latencies can be neglected.
The maximum utilization of the token ring when tt = 5 ms, tp = 3 ms, N = 15 is:
(tx)/(tx +(tp/N)) = (5)/(5+3/15) = 5/5.2 = .961