2 The table shows the activities involved in a project, their durations, precedences and the number of workers needed for each activity. The graph gives a schedule with each activity starting at its earliest possible time.
| Activity | Duration (hours) | Immediate predecessors | Number of workers |
| \(A\) | 3 | - | 3 |
| \(B\) | 5 | \(A\) | 2 |
| C | 3 | A | 2 |
| \(D\) | 3 | B | 1 |
| E | 3 | C | 3 |
| \(F\) | 5 | D, E | 2 |
| \(G\) | 3 | \(B , E\) | 3 |
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- Using the graph, find the minimum completion time for the project and state which activities are critical.
- Draw a resource histogram, using graph paper, assuming that there are no delays and that every activity starts at its earliest possible time.
Assume that only four workers are available but that they are equally skilled at all tasks. Assume also that once an activity has been started it continues until it is finished.
- The critical activities are to start at their earliest possible times. List the start times for the non-critical activities for completion of the project in the minimum possible time. What is this minimum completion time?