3 The table lists the activities involved in preparing for a cycle ride, their expected durations and their immediate predecessors.

1. Draw an activity network to represent the information in the table. Show the activities on the arcs and indicate the direction of each activity and dummy activity. You are advised to make your network quite large.
2. Carry out a forward pass and a backward pass to determine the minimum completion time for preparing for the ride. List the critical activities.
3. Construct a cascade chart, showing each activity starting at its earliest possible time. Two people, John and Kerry, are intending to go on the cycle ride. Activities \(A , B , F\) and \(G\) will each be done by just one person (either John or Kerry), but both are needed (at the same time) for activities \(C , D\) and \(E\). Also, each of John and Kerry must carry out activity \(H\), although not necessarily at the same time. All timings and precedences in the original table still apply.
4. Draw up a schedule showing which activities are done by each person at which times in order to complete preparing for the ride in the shortest time possible. The schedule should have three columns, the first showing times in 4-minute intervals, the second showing which activities John does and the third showing which activities Kerry does.