Question

A can finish a work in 20 days. A and B can together finish a work in 12 days.Then B alone can finish the work in

• A. 24 days
• B. 28 days
• C. 25 days
• D. 30 days

Answer 1

Answer:

D. 30 days

Total work = lcm[ 20, 12] = 60 A's efficiency = 60/20 = 3 A + B's efficiency = 60/12 = 5 B's efficiency = 5 - 3 = 2 Time taken by B alone to complete the work = Total work / B's efficiency = 60/2 = 30 days