Question

The efficiency of A, B, and C is 2 : 3 : 5. A alone can complete a work in 50 days. They all work together for 5 days and then C left the work, in how many days A and B together can complete the remaining work?

• A. 50 days
• B. 30 days
• C. 20 days
• D. 10 days

Answer 1

Answer:

D. 10 days

Total work = Efficiency × Time Let efficiency of A be 2 units/day Efficiency of A, B and C = 2 : 3 : 5 Total work = 2 × 50 = 100 units Work done by A, B and C in 5 days = (2 + 3 + 5) × 5 = 10 × 5 = 50 units Remaining work = 100 – 50 = 50 units ∴ Time taken by A and B to complete the remaining work = 50/(2 + 3) = 50/5 = 10 days