Question

A and B together can do a piece of work in 10 days. A alone can do it in 30 days. The time in which B alone can do it is

• A. 10 days
• B. 20 days
• C. 12 days
• D. 15 days

Answer 1

Answer:

D. 15 days

total work = lcm(10, 30) = 30 efficiency of A and B = 30/10 = 3 efficiency of A = 30/30 = 1 efficiency of B = 3 - 1 = 2 The time in which B alone can do the work = 30/2 = 15 days