Activity 7 is directly preceded by two activities-activity 5 and activity 6.Activity 5 has an expected duration of five and an ES time of six.Activity 6 has an expected duration of seven and an ES time of seven.Activity 7 has an expected duration of 10.The ES for activity 7 is:
A)11
B)14
C)21
D)24
E)25

Question

Quizplus · Accepted Answer

Activity 7 can only start after the completion of activities 5 and 6. Activity 5 has an ES time of 6 and takes 5 days to complete, therefore its latest finish time (LF) is 6+5-1=10. Activity 6 has an ES time of 7 and takes 7 days to complete, therefore its latest finish time (LF) is 7+7-1=13. Activity 7 has an expected duration of 10, so its latest start time (LS) is 13-10+1=4. Therefore, the earliest start time of activity 7 is the latest finish time of its predecessor activities, which is 13, and the ES of activity 7 is 13+1=14.

Activity 7 Is Directly Preceded by Two Activities-Activity 5 and Activity