Multiple choice

80 persons can build a wall of 400 m in 12 days working 8 hours in a day. Then in how many days 30 persons can build a wall of 300 m long working 6 hours in a day?

  1. 36

  2. 9

  3. 32

  4. 18

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

Using the chain rule: (80 persons × 12 days × 8 hours) / 400 m = (30 persons × D days × 6 hours) / 300 m. Simplifying: 7680/400 = 180D/300, giving D = 18 days.