A manufacturing cell consists of 12 identical machines. At any given time, one or more of the machines may be inoperable. The operator for the manufacturing cell troubleshoots machines and performs limited repair work. Occasionally, the operator requires more skilled technicians to complete repairs. Regardless of who performs the repairs, repair times for any machine is exponentially distributed with a mean of 30 minutes. The time until failure of an operating machine is exponentially distributed with a mean of 10 hours (a) If the operator/technician only work on a single machine at a time for repairs, what is the average number of operating machines in the manufacturing cell in the long run? (b) If there were two operators who could perform repairs simultaneously, what would the average number of operating machines be in the long run
