Multiple choice

40 men can build a wall 200 m. long in 12 days working 8 hrs. a day. The number of days 30 men will take to build a similar wall 300 m. long working 6 hrs. a day will be -

  1. 36

  2. 9

  3. 32

  4. 18

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

Work = men × days × hours. For first case: 200m wall needs 40 × 12 × 8 = 3840 man-hours. So 1m needs 3840/200 = 19.2 man-hours. For 300m wall: needs 300 × 19.2 = 5760 man-hours. With 30 men working 6 hours: days = 5760/(30 × 6) = 5760/180 = 32 days.