Multiple choice

A, B and C take 7, 12 and 14 days respectively to complete a job, working individually. With the help of D, A, B, and C together complete the work in 2 days. Find D's share in a total of Rs.4200 paid to them.

  1. Rs.600

  2. Rs.700

  3. Rs.1200

  4. Rs.1700

  5. None of these

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

A, B, C complete work in 7, 12, 14 days. Their combined rate = 1/7 + 1/12 + 1/14 = 25/84. With D, they finish in 2 days, so total rate = 1/2 = 42/84. D's rate = 42/84 - 25/84 = 17/84. D's contribution in 2 days = 2 × 17/84 = 34/84 of total work. Ratio D:ABC = 17:25. D's share = (17/42) × 4200 = Rs.1700.