Multiple choice

16 workers working 6 hours a day can build a wall of length 150 meters, breadth 20 meters, and height 12 meters in 25 days. In how many days 12 workers, working 8 hours a day can build a wall of 800 meters length, 15 meters breadth, and 6 meters height?

  1. 80 days

  2. 70 days

  3. 50 days

  4. 45 days

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

Volume1 = 150×20×12 = 36000. Volume2 = 800×15×6 = 72000 (double). Worker-hours1 = 16×6×25 = 2400. Worker-hours2 = 12×8×d. Using chain rule: 36000/2400 = 72000/(96d). Solving gives d = 50.