An average of 12 cars per hour arrive at a single-server
drive-in teller. Assume that the average service time for each
customer is 3 minutes, and both interarrival times and service
times are exponential.
a. What is the probability that the teller is idle?
b. What is the average number of cars waiting in line for the
teller? (A car that is being served is not considered to be waiting
in line.)
c. What is the average amount of time a drive-in customer spends
in the bank parking lot (including time in service)?
d. On average, how many customers per hour will be served by the
teller?