Consumers arrive at Homestake Bank between the hours of 10am and 11am according to a Poisson distribution at a mean rate of forty per hour. During the period from 10 A.M. to 11 A.M. the bank has 3 tellers working. The average time a teller spends with a customer is 3 minutes, and service time follows an exponential distribution. What is the average time a customer will spend waiting in line before seeing a teller?