The Quick Snap photo machine at the Lemon County bus station takes snapshots in exactly 80 seconds. Customers arrive at the machine according to a Poisson distribution at the mean rate of 15 per hour. On the basis of this information, determine the following:

(a.) the average number of customers waiting to use the photo machine (b.) the average time a customer spends in the system ( c) .the probability an arriving customer must wait for service. (Can I see the calculation)