Early morning espresso stand is staffed by 1 employee and server. Customers arrive to stand at rate of 20 per hour according to the Poisson distribution. Service time are exponentially distributed with the service rate of 30 customers per hour. i) Probability that server is busy is? ii) Find average number of customers waiting in line for service at early morning is? iii) Average time the customer waits in line for service at Early Morning is?