A crew of mechanics at the Highway Department Garage repair vehicles that break down at an average of = 7.5 vehicles per day (approximately Poisson in nature). The mechanic crew can service an average of = 12 vehicles per day with a repair time distribution that approximates a negative exponential distribution.

(a)What is the utilization rate for this service system?

(b)What is the average time before the facility can return a breakdown to service?

(c)How much of that time is spent waiting for service?

(d)How many vehicles are likely to be in the system at any one time?