A project consists of five activities $\text{(A, B, C, D and E)}$. The duration of each activity follows beta distribution. The three time estimates (in weeks) of each activity and immediate predecessor$(s)$ are listed in the table. The expected time of the project completion is ________________ weeks (in integer).
| Activity |
Time estimates (in weeks) |
Immediate
Predecessor(s) |
Optimistic
time |
Most likely
time |
Pessimistic
time |
| A |
4 |
5 |
6 |
None |
| B |
1 |
3 |
5 |
A |
| C |
1 |
2 |
3 |
A |
| D |
2 |
4 |
6 |
C |
| E |
3 |
4 |
5 |
B, D |