Multiple choice

Some staff promised to do a job in 18 days, but 6 of them went on leave, So the remaining men took 20 days to complete the job. How many men were there originally?

  1. 55

  2. 62

  3. 56

  4. 60
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let original men = M. Work = M × 18 man-days. When 6 men leave, M - 6 men take 20 days: (M-6) × 20 = M × 18. Solving: 20M - 120 = 18M, so 2M = 120, giving M = 60 men originally. This uses the inverse relationship between men and time for constant work.

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