A technician monitors a group of five computers that run an automated manufactoring facility. It takes an average of 15 minutes (exponentially distributed) to adjust a computer that develops a problem. The computers run for an average of 85 minutes (poisson distributed) without requiring adjustments. What is the (a) average number of computers waiting for adjustments? (b) average number o computers not in working order? (c) probability the system is empty? (d) average time in the quere? (e) average time in the system?