The number of buses that arrive at a bus stop in T minutes is a Poisson random variable B with expected value T/5.
(a) What is the PMF of B, the number of buses that arrive in T minutes? (
(b) What is the probability that in a two-minute interval, three buses will arrive?
(c) What is the probability of no buses arriving in a 10-minute interval?
(d) How much time should you allow so that with probability 0.99 at least one bus arrives?