Correct Answer - Option 5 : 45 days
Given:
A’s efficiency is double that of B
Time taken by A and B together to complete the work = 30 days
Concept Used:
If the ratio of the time taken by A and B is x ∶ y,
then the ratio of their efficiencies = y ∶ x
Calculation:
A’s 1 day work : B’s 1 day work = 2 : 1
(A + B)’s 1 day work = 1/30
After dividing (1/30)th work in 2 : 1 ratio,
A’s 1 day work = (1/30) × (2/3) = 1/45
∴ A alone can complete the work in 45 days.
