Multiple choice

4 men or 6 women or 9 boys can finish a work in 98 days, and then the number of days taken by 6 men, 4 women and 5 boys to finish the work is?

  1. 28 days

  2. 32 days

  3. 24 days

  4. 36 days

  5. None of these

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

4M = 6W = 9B = 1 unit of work in 98 days. Thus, 1M = 98/4, 1W = 98/6, 1B = 98/9 units per day. The combined rate of 6M + 4W + 5B is 6(1/98*4) + 4(1/98*6) + 5(1/98*9) = (6/4 + 4/6 + 5/9)/98 = (54+24+20)/(36*98) = 98/(36*98) = 1/36. The work is finished in 36 days.