A is twice as efficient as B. A and B together can complete a work in 12 days. In how many days can A alone complete the work?
Show answer & explanation
Correct answer: D
Explanation
Given:
A is twice as efficient as B.
A and B working together complete the task in 12 days.
Let B's work rate be 1.
Then A's work rate is 2.
The combined rate of A + B is 3.
Together, they complete the work in 12 days.
Total work = 12 × 3 = 36.
A's rate = 2.
Time taken by A alone = 36 / 2 = 18 days.