Multiple choice

$12$ workers can complete a piece of work in $10$ days. If the number of workers are reduced to $\dfrac {1}{3}rd$ of the original number, then how many more days would be required to complete the same work?

  1. $3$
  2. $5$
  3. $15$
  4. $20$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Original workers = 12, days = 10. New workers = 12 * (1/3) = 4. Using M1D1 = M2D2, 12 * 10 = 4 * D2, so D2 = 30 days. The question asks for 'how many more days', which is 30 - 10 = 20.

AI explanation

The total work is calculated as 12 workers multiplied by 10 days, giving 120 worker-days. If the workforce is reduced to one-third, the new team has 4 workers. Using the formula Work equals Men times Days, 120 worker-days equals 4 workers multiplied by the unknown days, which gives 30 days; subtracting the original 10 days shows 20 more days are required.

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