A Bank of Ten Machines Requires Regular Periodic Service

Multiple Choice

A bank of ten machines requires regular periodic service.Machine running time and service time are both exponential.Machines run for an average of 44 minutes between service requirements,and service time averages 6 minutes per machine. If operators cost $15 per hour in wages and fringe benefits and machine downtime costs $75 per hour in lost production,what is the optimal number of operators for this bank of machines?

A) 1
B) 2
C) 3
D) 4
E) 5