There are two servers available to process n jobs. Initially, each server begins work on a job. Whenever a server completes work on a job, that job leaves the system and the server begins processing a new job (provided there are still jobs waiting to be processed). Let T denote the time until all jobs have been processed.

If the time that it takes server i to process a job is exponentially distributed with rate μi, i = 1, 2, find E[T ] and Var(T ).