Metalco is in the process of hiring a repairperson for a 10-machine shop. Two candidates are under consideration. The first candidate can carry out repairs at the rate of 5 machines per hour and earns $15 an hour. The second candidate, being more skilled, receives $20 an hour and can repair 8 machines per hour. Metalco estimates that each broken machine will incur a cost of $50 an hour because of lost production.

Assuming that machines break down according to a Poisson distribution with a mean of 3 per hour and that repair time is exponential, which repairperson should be hired?