Can you please do it using formulas and not just excel I want to know the concept.

ACTIVITY a m m b IMMEDIATE PREDECESSOR(S) HIFI A 3 6 8 B 2 4 4. C 1 2 3 D 6 7 8 C E 2 4. 6 BD 4 F 6 10 . G 1 2. 14 . H 3 6 9 F 10 11 12 G 14 16 20 C K 2. 8 10 HT a. Detenine the expected completion time and variance for each activity. b. Determine the total project completion time and the critical path for the project. c. Determine ES, EF, LS LF and slack for each activity. d. What is the probability that Kelle Carpet and Trim will finish the project in 40 days or less? Be