A: In one day A can do work of 1/20, 1/30 and 1/60 of B and C. So A can do the work in 1/20 + 1/30 + 1/60 = 15 days. The answer is (C).
Answer the following multiple choice question with options (a), (b), (c), (d), (e) by reasoning step-by-step.
Q:A, B and C can do a piece of work in 20, 30 and 60 days respectively. In how many days can A do the work if he is assisted by B and C on every third day? Answer Choices: A)12 B)13 C)15 D)16 E)18