Consider the single-queue model where only one customer is allowed in the system.

Customers who arrive and find the facility busy never return. Assume that the arrivals distribution is Poisson with mean l per unit time and that the service time is exponential with mean 1m time units.

(a) Set up the transition diagram and determine the balance equations.

(b) Determine the steady-state probabilities.

(c) Determine the average number in the system.