The MVD employs five representative to help customers renew…

The MVD employs five representative to help customers renew their driver’s licenses. Suppose that, on average, a customer arrives every 3 minutes and that it takes a representative an average of 12 minutes to assist her/him. Both inter-arrival and activity times are exponentially distributed. The state estimates that each minute a customer has to wait costs $1 in lost productivity. What is the server utilization?