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19 Apr 2026, 19:00
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C
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
25%
(medium)
Question Stats:
85% (02:31) correct
15%
(02:36)
wrong
based on 68
sessions
History
Date
Time
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Not Attempted Yet
40 men take 60 hours to refine 200 units of stone. How long will it take 60 men to refine 800 units of stone if the new team is 20% less efficient?
A. 20 hours
B. 25 hours
C. 200 hours
D. 240 hours
E. 250 hours
A. 20 hours
B. 25 hours
C. 200 hours
D. 240 hours
E. 250 hours
BongBideshini
Joined: 25 May 2021
Last visit: 11 May 2026
Posts: 199
Given Kudos: 82
Location: India
Concentration: Entrepreneurship, Marketing
Schools: HBS '27 Stanford '27 Wharton '27 Sloan '27
GPA: 3.8
WE:Engineering (Government)
Products:
19 Apr 2026, 22:58
Kudos
Bookmarks
| Men | Efficiency (units/hr) | time | total work |
| 40 M | =200/60 | 60 | 200 |
| 1 M | =200/(60*40) =1/12 | ||
| 1 M | new efficiency =0.8/12 =1/15 | ||
| 60 M | =60/15 =4 | ||
| 60 M | 4 | =800/4 =200 | 800 |
| Ans | 200 |
Ans C
ExpertsGlobal5
19 Apr 2026, 23:02
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Bookmarks
Base rate: 40×60=2400 man-hours produce 200 units ⇒ 1 man-hour = 1/12 unit.
New efficiency is 20% lower ⇒ rate becomes 1/12×0.8=1/15 per man-hour.
With 60 men: total rate = 60×1/15=4 units/hour.
Time for 800 units = 800/4=200 hours.
Answer: C (200 hours)
New efficiency is 20% lower ⇒ rate becomes 1/12×0.8=1/15 per man-hour.
With 60 men: total rate = 60×1/15=4 units/hour.
Time for 800 units = 800/4=200 hours.
Answer: C (200 hours)
