Multiple choice

16 men can do a piece of work in 10 days. How many men are needed to complete that work in 40 days?

  1. 32

  2. 16

  3. 40

  4. 4

  5. 64
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Work is constant, so men × days = constant. 16 × 10 = 160 man-days of total work. To complete the same 160 man-days in 40 days, you need 160/40 = 4 men. This is inverse variation: doubling the time halves the workers needed.

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