Consider a bank with four tellers. Tellers 3 and 4 deal only with business accounts, while Tellers 1 and 2 deal with general accounts. Clients arrive at bank at a rate of one 8 every 3±1 minutes. Of the clients, 33% are business accounts. Clients randomly choose between the two tellers available for each type of account. (Assume that a customer chooses a line without regard to its length and does not change lines). Business accounts take 15±10 minutes to complete and general accounts take 6±5 to complete. Simulate the system for 500 transactions to be completed. What percentage of time is each type of teller busy? What is the average time that each type of customer spends in the bank?

a. Obtain the results of the problem by simulating in MS Excel.

b. Obtain the results of the problem by simulating in ARENA.