Due to Turnover and Promotion, a Bank Manager Knows That

Short Answer

Due to turnover and promotion, a bank manager knows that, on average, she hires four new tellers per year. Suppose the number of tellers she hires is Poisson distributed.
A) What is the probability that in a given year, the manager hires exactly five new tellers?
B) What is the average number of tellers the manager hires in a six-month period?
C) What is the probability that the manager hires at least one new teller in a given six-month period?