Q$1.$ Western National bank is considering opening a drive$-$through window for customer Service. Management estimates that customers will arrive at the rate of $15$ per hour and the teller who will staff the window can service customers at the rate of one every three minutes.

Assuming Poisson arrivals and exponential service, find

$1$ Utilization of the teller.

$2.$Average number in the waiting Line.

$3$ Average number in the system.

$4.$ Average waiting time in Line.

$5$ Average waiting time in the System.

Q$2.$American Vending Inc supplies vended food to a large university. Because students often kick the machines out of anger and frustration, management has a constant repair problem. The machine