This question-specific review guide is tied to the answer reasoning for a PracticeTestVault item. Use it after you answer the question so the review stays focused on what the prompt actually tested.
What this question is testing
Objective: Calculate a PERT expected duration
Prompt focus: An activity has an optimistic duration of 6 days, a most likely duration of 9 days, and a pessimistic duration of 18 days. Using the PERT weighted average, what expected duration should the scheduler use?
Why the correct answer works
10 days
PERT expected duration = (O + 4M + P) / 6 = (6 + 4 x 9 + 18) / 6 = 10 days.
Why the tempting wrong answer fails
The tempting wrong answer usually loses because it skips the key condition, priority, or evidence in the prompt.
Plain-language takeaway
PERT expected duration = (O + 4M + P) / 6 = (6 + 4 x 9 + 18) / 6 = 10 days. Interpret the result in the schedule context before recommending action.
Simple analogy
Think of calculate a pert expected duration like following a short checklist: identify the clue, confirm the rule, and then make the move that fits this exact scenario.
How to review it before a retake
- Underline the command word and name what the question is asking before rereading the choices.
- Compare the correct answer against the closest distractor and write the exact detail that separates them.
- Retest this objective with a fresh question without looking at the rationale first.