Consider an Espresso Stand with a Single Barista

Multiple Choice

Consider an espresso stand with a single barista.Customers arrive to the stand at the rate of 28 per hour according to a Poisson distribution.Service times are exponentially distributed with a service rate of 35 customers per hour.The probability that the server is idle is

A) 0.20
B) 0.60
C) 0.80
D) 1.00