A can complete a work in 18 days. If B is only 90% efficient as compared to A, then in how many days will B alone complete the same work?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 20.
Efficiency (A : B) = 10 : 9
B's time = 18 × (10/9) = 20 days