What is the critical path for the project shown in the PERT chart?

• A. A-B-J
• B. A-C-D
• C. B-C-E
• D. A-B-C

Answer: (A)

In this PERT context, the key idea is that the critical path is the route through the project network that takes the longest total time and has zero slack. Any delay on tasks along this path pushes the project finish date.

The path from A to B to J is the longest-duration sequence and, crucially, its tasks carry no slack. That means there is no room to delay A, B, or J without extending the project completion. Other routes, like A–C–D, B–C–E, or A–B–C, have some slack, so delays there wouldn’t necessarily delay the finish date unless that slack is consumed. Therefore, the path A → B → J is the critical path.