Suppose the store has two docks and trucks arrive at the rate of $8$ trucks per hour. Arriving trucks join a single line and then proceed to the first available empty dock. The rest stays unchanged.

a$)$ What is the average interarrival time of trucks?

b$)$ What is the utilization of the dock?

c$)$ What is the average waiting time of the trucks?

d$)$ What is the average number of trucks waiting?

e$)$ What is the average number of trucks at the store $($waiting $+$loading$)?$