Which Server Serves The Customer Three servers are working in parallel and have service time distributions given by S1, S2 and S3. The distribution S1 is exponential with mean 20 minutes. The distribution S2 is normal with mean 20 minutes and standard deviation 5 minutes. The distribution S3 is uniform in the range between 10 minutes and 30 minutes. A customer comes in and finds that all three servers are available, and the customer can pick either of the three servers at random (each with a probability of 1/3). If the customer leaves after 22 minutes, compute the probability that the customer was served by server #3.