A is twice as efficient as B. Together, they can complete a task in 12 days. How many days will A alone take to complete the task?
Show answer & explanation
Correct answer: B
Explanation
Let B's efficiency = 1
Then A's efficiency = 2
Combined efficiency of both = 1 + 2 = 3
Time taken by both to complete the work = 12 days
Total work = 3 × 12 = 36 units
Time taken by A alone = 36 ÷ 2 = 18 days