You own a truck repair garage that has just one mechanic and one repair bay. The mechanic takes on average 20 minutes to fit a new engine. Customers currently arrive at an average rate of 2 per hour during the 8-hour business day. You are concerned that the length of time customers have to wait may be driving business away.

a. Compute the following quantities:

i. the average time a customer spends in the garage;

ii. the average number of cars waiting for service at any one time;

iii. the probability that the number in the queue exceeds 2.

State clearly the assumptions you are making. [