Consider the situation of Mr. R. B. Cheney, who owns a large gas station on a highway in Vermont. In the afternoon hours, there are, on average, 1,000 cars per hour passing by the gas station, of which 2 percent would be willing to stop for refueling. How- ever, since there are several other gas stations with similar prices on the highway, potential customers are not willing to wait and bypass Cheney's gas station. The gas station has six spots that can be used for filling up vehicles and it takes a car, on average, five minutes to free up the spot again (includes filling up and any potential delay caused by the customer going inside the gas station).
a. What is the probability that all six spots are taken?
b. How many customers are served every hour?