At Mercy Hospital, two workers process insurance claims every day. Insurance claims arrive to be processed on an average of one every 10 minutes throughout the day. It takes an average of 12 minutes to process. Both time between arrivals and service times are exponentially distributed.

 (1) What is the expected number of claims waiting to be processed?

 (2) What is the probability that both workers are busy?

 (3) What is the effect on performance if a third worker, working at the same speed as the first two, is added to the system? Repeat (1) and (2).