Introduction to Management Science 12th Edition by Bernard Taylor

Exercise 37

The Clip Joint is a hairstyling salon at University Mall. Four stylists are always available to serve customers on a first-come, first-served basis. Customers arrive at an average rate of 5 per hour, and the stylists spend an average of 35 minutes on each customer.
a. Determine the average number of customers in the salon, the average time a customer must wait, and the average number waiting to be served.
b. The salon manager is considering adding a fifth stylist. Would this have a significant impact on waiting time