Telephone calls arrive at the rate of 48 per hour at the reservation desk for Regional Airways. 

a. Find the probability of receiving 3 calls in a 5-minute interval.

b. Find the probability of receiving 10 calls in 15 minutes.

c. Suppose that no calls are currently on hold. If the agent takes 5 minutes to complete processing the current call, how many callers do you expect to be waiting by that time? What is the probability that no one will be waiting?

d. If no calls are currently being processed, what is the probability the agent can take 3 minutes for personal time without being interrupted?