A technician monitors a group of 5 computers that run an automated manufacturing facility. It takes an average of 15 minutes (negative exponentially distributed) to adjust a computer that develops a problem. On average, one of the computers requires adjustment every 85 minutes. Determine the following:
a) The average number of computers waiting for adjustment (i.e., in the queue)
b) The average number in the system
c) The probability no computer needs adjustment.