Network Analysis (CPM and PERT)
JKSSB Junior Engineer (Civil) · Construction Planning and Management · 27 practice questions with answers and explanations: 16 Easy, 8 Medium, 3 Hard.
Sample questions
Sample Easy question 1
The total float of an activity is:
- Earliest finish minus latest start
- Latest start time minus earliest start time
- Duration minus the earliest start
- Earliest start minus latest finish
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Answer: B. Total float = LST − EST, which also equals LFT − EFT.
Sample Easy question 2
Free float is the delay possible in an activity without affecting:
- The earliest start of the succeeding activity
- The latest finish of the project
- The project cost
- The critical path
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Answer: A. Free float is the spare time that does not disturb the following activity.
Sample Easy question 3
A dummy activity in a network:
- Is always on the critical path
- Consumes no time or resource and shows a logical link
- Consumes time but no resource
- Shows the final activity
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Answer: B. Dummies keep the logic of the network correct.
Sample Medium question 4
The activities on the critical path have variances of 4, 9, 1 days². The standard deviation of the project duration is about:
- 7.48 days
- 3.74 days
- 14 days
- 1.87 days
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Answer: B. σ = √(4 + 9 + 1) = √14 = 3.74 days.
Sample Medium question 5
The latest event time of an event is 18 days and its earliest event time is 14 days. The event slack is:
- 4 days
- 32 days
- 18 days
- 14 days
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Answer: A. Slack = TL − TE.
Sample Medium question 6
The latest finish time of the last activity is 12 days and its duration is 3 days. The latest start time is:
- 9 days
- 15 days
- 3 days
- 12 days
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Answer: A. LST = LFT − duration.
Sample Hard question 7
In a network, A (4 days) is followed by B (6 days) or C (5 days) in parallel, and then by D (3 days). The project duration is:
- 10 days
- 13 days
- 12 days
- 18 days
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Answer: B. The critical path A-B-D takes 4 + 6 + 3 = 13 days, and A-C-D takes 12.
Sample Hard question 8
An activity takes 10 days at a normal cost of ₹10,000 and 7 days at a crash cost of ₹16,000. Its cost slope is:
- ₹2,000 per day
- ₹1,000 per day
- ₹6,000 per day
- ₹3,000 per day
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Answer: A. Slope = (16,000 − 10,000) ÷ (10 − 7) = ₹2,000 per day.
Sample Hard question 9
A network has two paths to its final event: A (2 days), C (5 days), E (3 days) and B (4 days), D (4 days), E (3 days). The project duration is:
- 10 days
- 13 days
- 11 days
- 21 days
Show answer
Answer: C. Path A-C-E takes 10 days and path B-D-E takes 11 days. The longer, 11 days, is the critical path.