During periods of peak demand, on average a new customer arrives at the drive-thru of a restaurant every 2 minutes (assume Poisson arrival pattern). The drive-thru only has one service window. The average rate of service during 

these periods is 40 customers per hour.

 

a. On average, how much time do customers end up waiting in their vehicles before being served?

b. What is the average number of vehicles in the system during these peak demand periods?

c. How busy (utilization) is the drive-thru during these periods of peak demand?

d. What is the probability that there are no customers at the drive-thru during periods of peak demand?

e. What is the probability that there will be more than 3 customers in the system during periods of peak demand?