20 points) Suppose that the Starbucks Coffee Branch in Question 1(above) has now 3 tellers but service time for each customer is 6 minutes. Determine the following: a. Write the Queueing Model with proper notation that includes the assumptions of the queueing system and the expected number of customers present in the shop (12 points) b. The expected length of time a customer spends in the queue (3 points) c. The fraction of time that a particular teller is idle (5 points)