Chapter Project Scheduling: PERT/CPM, Problem 12 12. Assume that the activity time estimates (in days) for the swimming pool construction project in Problem 11 are as follows: Activity Optimistic Most Pessimistic Probable A 5 6 B 6 D 10 10 H 10 5 a. What are the critical activities? b. What is the expected time to complete the project? c. Based only on the critical path, what is the estimated probability that the project can be completed in 25 or fewer days