Multiple choice

Directions: Select the correct alternative from the given choices. A contractor observed that with the existing number of workers, he could finish a project in 12 days. However, if he added 20 more workers to the existing team, the project will be completed in 10 days. How many days would a single worker take to complete the entire project?

  1. 480

  2. 600

  3. 800

  4. 1200
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let x be the number of workers. Work = x * 12. Also Work = (x+20) * 10. 12x = 10x + 200, 2x = 200, x = 100. Total work = 100 * 12 = 1200 worker-days.

AI explanation

Let the original number of workers be W. The total work is 12W, and with 20 additional workers the work is 10(W + 20). Equating the two gives 12W = 10W + 200, so W is 100 workers. The total amount of work is 12 days multiplied by 100 workers, which is 1200 man-days. A single worker would therefore take 1200 days to complete the entire project.

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