Multiple choice

If 9 men working 7.5 hours a day can finish a piece of work in 20 days, then how many days will be taken by 12 men, working 6 hours a day to finish the work? It is being given that 2 men of latter type work as much as 3 men of the former type?

  1. 10.5

  2. 11

  3. 6

  4. 12.5

  5. 13
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The total work is 9 men * 7.5 hours * 20 days = 1350 man-hours. Given 2 men (latter) = 3 men (former), 1 latter man = 1.5 former men. So 12 latter men = 18 former men. Work = 18 * 6 * D = 1350. D = 1350 / 108 = 12.5.

AI explanation

The total work for the first group is 9 men multiplied by 7.5 hours multiplied by 20 days, yielding 1350 man-hours. Since 2 men of the latter type equal 3 men of the former type, the efficiency ratio of latter to former is 3 to 2, making the 12 new men equivalent to 18 original men. Using the work formula (Men1 times Hours1 times Days1 equals Men2 times Hours2 times Days2), 1350 equals 18 times 6 times the new number of days; solving this gives 12.5 days.

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