On average, 100 customers arrive per hour at the Gotham City Bank. The average service time for each customer is one minute. Service times and interarrival times are exponentially distributed. The manager wants to ensure that no more than 1% of all customers will have to wait in line for more than five minutes. If the bank follows the policy of having all customers join a single line, how many tellers must the bank hire?

The following four problems are optional. They are based on the limited queue and limited source models in the Limited Queue Template.xlsm and Limited Source Template.xlsm files.