GATE 2022 MN – Question 65
PERT activities list predecessor→successor events and (pessimistic, most likely, optimistic) weeks: A 1→2(20, 15, 4), B 1→3(12, 8, 4), C 2→3(16, 11, 6), D 3→4(20, 13, 12), E 2→4(13, 8, 3), F 1→4(45, 35, 25). Find expected project duration in weeks, as an integer.
Practise this question in The GATE Grind →
Show answer and explanation
Correct answer: 39 to 39
Explanation
PERT means are (a+4m+b)/6. This gives A 14, B 8, C 11, D 14, E 8 and F 35 weeks. Path durations are A–C–D:39, A–E:22, B–D:22 and F:35. The longest expected path is A–C–D, so project duration is 39 weeks. All predecessor constraints must be respected; direct activity F is not the critical path.