A service facility consists of one server who can serve an average of two customers per hour (service times are exponential). An average of three customers per hour arrive at the facility...

A service facility consists of one server who can serve an average of two customers per hour (service times are exponential). An average of three customers per hour arrive at the facility (interarrival times are assumed to be exponential). The system capacity is three customers: two waiting and one being served.

a. On average, how many potential customers enter the system each hour?

b. What is the probability that the server is busy at a typical point in time?