3. A project network is shown below. Precedence Optimistic Most Probable Pessimistic Activity Activities Time (weeks) A 10 B 2 4 8 C -- 4 8 12 D A, B 2 4 8 E C 10 12 14 C 4 10 16 G D, E 1 3 H E 1 2 E, F 2 a. What is the expected completion time of this project? b. What is the probability that the project can be completed within 27 weeks