The local grocery store consists of two cashiers. The customers arrive according to the Poisson Distribution and the service times are based on negative exponential distribution. The average customer service time is five minutes and the average time between the arrivals of successive customers is 3 minutes. On the average, hom much time will the customer spend in line waiting to be served?
a. 16.2 minutes
b. 14.4 minutes
c. 18.2 minutes
d. 13.6 minutes
e. 11.2 minutes