Multiple choice

A certain number of men can do a piece of work in 40 days. If there were 45 men more, the work could have been finished in 25 days. Find the original number of men employed in the work.

  1. 70

  2. 85

  3. 65

  4. 75
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let original men = M. Work = M × 40 man-days. With 45 more men: (M + 45) × 25 = M × 40. Solving: 25M + 1125 = 40M, so 15M = 1125, giving M = 75 men originally. This follows from the inverse proportionality - more men means fewer days needed.

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