A crew of mechanics at the highway department garage repair vehicles that break down at an average of 3 vehicles every 12 minutes (approximately poisson in nature). the mechanic crew can service an average of 3 vehicles every 10 minutes with a repair time distribution that approximates an exponential distribution. the crew cost is approximately $150 per hour. the cost associated with lost productivity from the breakdown is estimated at $50 per hour. which is cheaper, the existing system with one service crew or a revised system with two service crews? note that the average waiting time for adding the second crew is 0.01.