A hardware store operates a single-server queuing system (with one cashier and one checkout counter) 12 hours per day. Assume that there is no limit on the customer population. Inter-arrival times and service times are exponentially distributed. Customers arrive at the checking counter queue at a rate of 20 customers/hr. Customers can be checked out at a rate of 25 customers/hr.

• What is the average waiting time in the queue?

The manager of this store feels that if the queue is divided into two equal parts and a second checkout counter is operated, there would be greater efficiency." The customers would form a single queue.

• What is the average waiting time in the queue?