Problem 3: Engineering Project (25=10pts) Consider an engineering project consisting of four activities A,B,C, and D. The following are constraints within which the project has to be conducted - A and B, the first activities of the project, can be started simultaneously. - C can be started only after A is completed. - D can be started only after B is completed Suppose the activity times for the activities are A=4 weeks, B=3 weeks, C=2 weeks, D=3 weeks. a) How long does the project take to complete? b) We ask the engineers working on activity A to factor in uncertainty in activity times and to provide better estimates of the activity times. The engineers tell us that activity A takes 2 weeks 25% of the time, 4 weeks 50% of the time and 6 weeks 25% of the time. How long does the project now take to complete (on average)