Midtown Bank always has two tellers on duty. Customers arrive to receive service from a teller at a mean rate of 40 per hour.

A teller requires an average of 2 minutes to serve a customer. When both tellers are busy, an arriving customer joins a single line to wait for service. Experience has shown that customers wait in line an average of 1 minute before service begins.

(a) Describe why this is a queueing system.

(b) Determine the basic measures of performance—Wq, W, Lq, and L—for this queueing system. (Hint: We don’t know the probability distributions of interarrival times and service times for this queueing system, so you will need to use the relationships between these measures of performance to help answer the question.)