Upon arrival, a customer either enters service if the server is free or joins the waiting line. When the server completes work on a customer, the next one in line (i.e., the one who has been waiting the longest) enters service. An Ser (a) Determine the departure times of these 13 customers. (b) Repeat (a) when there are two servers and a customer can be served by either one. (c) Repeat (a) under the new assumption that when the server completes a service, the next customer to enter service is the one that has been waiting the least time