plz help me solve the questions

A small software development project at Krishna Dhir's firm has five major activities. The times are estimated and provided in the table below. a) Find the expected completion time for this project. The expected completion time for this project is (enter your response as a whole number). b) What variance value would be used to find probabilities of finishing by a certain time? The project variance value of completion time is (enter your response as a whole number). The following is a table of activities associated with a project at Rafay Ishfaq's software firm in Chicago, their durations, what activities each must precede and the crash cost to reduce duration per week: Suppose that Rafay is only given 6 weeks (instead of 9) to complete the project. By how many weeks should each activity be crashed in order to meet the deadline? Assume that you can crash an activity down to 0 weeks duration. What is the total crashing cost? $ (Enter your response as a whole number.)