Problem: An activity has an optimistic time estimate of 15 days, a most likely estimate of 24 days, and a pessimistic estimate of 40 days. What is the expected PERT duration of the activity?
A) less than 27 days but greater than or equal to 26 days
B) less than 25 days but greater than or equal to 24 days
C) less than 26 days but greater than or equal to 25 days
D) less than 24 days