consider a two server system which a customer is served first by server 1, then by server 2 and then departs. The server times at server I are exponential random variables with rate ui I = 1,2.
a)When you arrive you find server 1 free and you find server one is free and one customers at server 2 .find the expected time that you spend in the system?

b)a)When you arrive you find server 1 free and you find server one is free and two customers at server 2 .find the expected time that you spend in the system?