Assume the interarrival times of customers to a copy center are exponentially distributed with amen interarrival time of 4 minutes. (a) Suppose a customer arrives at 8:00 am, what is

the probability that the next customer arrives after 8:12 am? (b) Suppose a customer arrives at 8:00 am, you observe that no customer arrives between 8:00 am-and 8:16 am, what is the probability that the next customer arrives before 8:20 am? (c) What is the probability that three customers arrive between 8:00 am and 8:20 am? (d) What is the average number of arriving customers between 8:00 am and 11:00 am?