Introduction to Management Science 12th Edition by Bernard Taylor

Exercise 3

In Problem, suppose that Moore's television repair service cannot accommodate more than 30 TV sets at a time. What is the probability that the number of TV sets on hand (under repair and waiting for service) will exceed the shop capacity
Problem
Moore's television repair service receives an average of six TV sets per 8-hour day to be repaired. The service manager would like to be able to tell customers that they can expect 1-day service. What average repair time per set will the repair shop have to achieve to provide 1-day service, on average (Assume that the arrival rate is Poisson distributed and repair times are exponentially distributed.)