Neve Commercial Bank is the only bank in the town of York, Pennsylvania. On a typical Friday, averages of 10 customers per hour arrive at the bank to transact business. There is currently one teller at the bank, and the average time required to transact business is 4 minutes. It is assumed that service times may be described by the exponential distribution. If a single teller is used, find:

The average time in the line.

The average number in the line.

The average time in the system.

The average number in the system.

The probability that the bank is empty.

CEO Benjamin Neve is considering adding a second teller (who would work at the same rate as the first) to reduce the waiting time for customers. A single line would be used, and the customer at the front of the line would go to the first avail-able bank teller. He assumes that this will cut the waiting time in half. If a second teller is added, find the new answers to parts (a) to (e).