$[2$ Points$]$ Consider an $\frac{M}{M}\frac{?}{k}$ queueing system that entails $k=3$ homogeneous servers. If the arrival

rate is $3$ requests$/$second and service rate for each server is $4$ requests$/$second$.$ If the probability that an

arriving job must queue because it finds all $3$ servers busy is $0\mathrm{.}3,$ then find:

a$)$ The expected number of jobs waiting in the queue?

b$)$ The expected waiting time for each job in the queue?