An open mic night at a local caf is popular on Wednesday nights. Between 8-10 p.m., a performer arrives on average every 3.5 minutes. The performers sign up on a first-come, first serve basis and each performer is asked to keep their songs short. Most performers abide by this, and the average performance time is 3 minutes. Assume Poisson arrivals and exponential performance times.

a) What is the utilization of the performance stage?

b) What is the average time (in minutes) a performer waits to get on stage?

c) On average how many performers are in the caf?