21. Consider a project consisting of the following 7 activities. The optimistic, most likely, and pessimistic times, as well as a predecessor for each activity, are given in the table. The precedence relationship is finish-to-start for all the activities in the project.

a) Using the most likely times, apply the Critical Path Analysis method to find out the critical path and the total expected time to complete the project.

b) What is the earliest and latest start time for activity C?

c) Use PERT to calculate the expected time for all the activities.

d) Using the calculated expected times, apply the Critical Path Analysis method to find out the critical path and the total expected time to complete the project.

e) What is the probability that the project is completed in less than 70 days?

Predecessor Optimistic time Most likely time Pessimistic time Activity 3 days 5 days 7 days A B. A 12 days 15 days 18 days 20 days 25 days 42 days B. 24 days 26 days 28 days B 26 days 30 days 34 days F C,D 3 days 10 days 11 days G E,F 8 days 10 days 18 day