Multiple choice

A group of workers can complete a job in 120 days. If there were 4 more such workers then the work could be finished in 12 days less. What was the actual strength of workers?

  1. 30

  2. 40

  3. 42

  4. 36

  5. None of these

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let n be the number of workers. Work = n × 120 worker-days. With n+4 workers, time = 120-12 = 108 days. Work = (n+4) × 108. Equating: 120n = 108(n+4). 120n = 108n + 432. 12n = 432. n = 36.