Refer to the previous question. Create a spreadsheet model to simulate the completion times for servicing cars. Assume that activity times follow a triangular distribution, and perform 500 replications on the model.

a. Estimate the probability of each activity falling on the critical path.
b. On average, how long should it take to finish servicing a car?
c. Suppose that the manager of this business wants to guarantee that your car will be ready within 10 minutes or you will receive a coupon worth $5 off your next visit. What proportion of customers will receive the coupon?