please solve them all

Q3-A project being analyzed by PERT has 60 activities, 13 of which are on the critical path. If the estimated time along the critical path is 214 days with a project variance of 169 , what is the probability that the project will be completed within 224 days? Please show all details and use two decimals in your answer. Q4-An activity on a PERT network has these time estimates: optimistic =2, most likely =3, and pessimistic =8. What is its expected activity time and variance? Please show all details and use two decimals in your answer Q17-A project network consists of the activities in the following list. Times are given in weeks. Calculate the ES, EF, LS, LF, and Slack for each activity and determine the critical path. What is the project completion time? 34-Two critical path activities are candidates for crashing on a CPM network. Activity details are in the table below. To cut two days from the project's duration, activity should be crashed first, adding to project cost and activity should be crashed second, adding to project cost. 35-The critical path for the network activities shown below is with duration