PMI Exam Questions

What time will you record for this activity?

You are the project manager for your organization. You have recorded the following duration
estimates for an activity in your project: optimistic 20, most likely 45, pessimistic 90. What time will
you record for this activity?

A.
48

B.
20o, 45m, 90p

C.
90

D.
45

Explanation:
This is an example of a three-point estimate. A three-point estimate records the optimistic, most
likely, and the pessimistic duration, and then records an average for the predicted duration Three-point estimate is a way to enhance the accuracy of activity duration estimates. This concept is

originated with the Program Evaluation and Review Technique (PERT). PERT charts the following
three estimates: Most likely (TM): The duration of activity based on realistic factors such as
resources assigned, interruptions, etc.
Optimistic (TO): The activity duration based on the best-case scenario
Pessimistic (TP): The activity duration based on the worst-case scenario
The expected (TE) activity duration is a weighted average of these three estimates:
TE = (TO + 4TM + TP) / 6
Duration estimates based on the above equations (sometimes simple average of the three
estimates is also used) provide more accuracy. It can be calculated as follows:
TE = ( 20 + 45*4 + 90) / 6
= 290/6
=48
Answer options B, C, and D are incorrect. These are not the valid answers for this question.