A small gas station has two pumps. Pump $1$ is self$-$service and pump $2$ is full service. About $75\%$ of the customers go to pump $1$ and the other $25\%$ go to pump $2.$ During a busy hour, customers arrive at the gas station according to the probability distribution in the following table Time Between Arrivals $($Minutes$)$ Probability $0\mathrm{.}050\mathrm{.}150\mathrm{.}200\mathrm{.}400\mathrm{.}201\mathrm{.}00$ Total Because some customers pay at the pump and others pay at the casher inside, there is a big difference in the time needed at the pumps. The following tables give the respective probability distributions of the time required by each customer at thc pumps Pump $1$ Servic