An equipment maintenance building is to be erected near a large construction site. An electric generator and a large water storage tank are to be installed a short distance away and connected to the building. The activity descriptions and estimated duration times ( a= optimistic, m= most likely, p= pessimistic), along with the required activity precedence relationships are given as follows: Time (a) What is the probability the project will be completed in 16 weeks or less? (b) Determine the probability that the project will be completed in 19 weeks or less. (c) Determine the probability that the project will require 15 or more weeks for completion