George can do a piece of work in 8 hours. Paul can do the same work in 10…
2026
George can do a piece of work in 8 hours. Paul can do the same work in 10 hours, Hari can do the same work in 12 hours. George, paul and hari start the same work at 9 am, while george stops at 11 am, the remaining two complete the work. What time will the work complete?
Answer: D. 1 pm — Correct approach and calculation: Choose a convenient total work: 120 units (LCM of 8, 10, 12). Compute individual rates: George = 120/8 = 15 units/hr, Paul =…
- A.
11.30 am
- B.
12 noon
- C.
12.30 pm
- D.
1 pm
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Show answer & explanation
Correct answer: D
Correct approach and calculation:
Choose a convenient total work: 120 units (LCM of 8, 10, 12).
Compute individual rates: George = 120/8 = 15 units/hr, Paul = 120/10 = 12 units/hr, Hari = 120/12 = 10 units/hr.
Work done from 9:00 to 11:00 (2 hours) by all three = 2 × (15 + 12 + 10) = 2 × 37 = 74 units.
Remaining work = 120 − 74 = 46 units.
Paul and Hari together do 12 + 10 = 22 units/hr. Time to finish the remaining 46 units = 46/22 = 2.090909… hours = 2 hours + 1/11 hour.
Convert 1/11 hour to minutes: (60/11) ≈ 5.4545 minutes = 5 minutes 27 seconds (approximately).
So the work finishes at 11:00 + 2 hours 5 minutes 27 seconds ≈ 1:05:27 pm (approximately 1:05 pm).
Note: None of the given options (11:30 am, 12:00 noon, 12:30 pm, 1:00 pm) exactly match this result. The closest option is 1:00 pm, but it is about 5 minutes earlier than the precise completion time.