Multiple choice general knowledge math & puzzles

If 6 men can do a piece of work in 30 days of 9 hours each, how many men will it take to do 10 times the amount of work if they work for 25 days of 8 hours?

  1. 62

  2. 40

  3. 81

  4. 100

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Original work = 6 x 30 x 9 = 1620 man-hours. Ten times that is 16200 man-hours. The new schedule gives 25 x 8 = 200 hours per man, so men needed = 16200 / 200 = 81, matching option C.