Sharp discount Wholesale club has two service desks, one at each entrance of the store. Customers arrive at each customer service desk at an average of one every six minutes. The service rate at each service desk is about 5 minutes per customer.
a. How often is each service desk idle?
b. What is the probability that both service desk clerks are busy?
c. How much time does a customer spend at the service desk?
d. How many customers are waiting in the line in front of each service desk, an average?