Correct Answer - Option 4 : 16 days
Given:
Time taken by A to complete the work = 20 days.
B is 25% more efficient than A
Calculation:
Let the time taken by B to complete the work = x days
Ratio of time taken by B and A = 125 : 100 = 5 : 4
⇒ 5 : 4 ∷ 20 : x
⇒ x = (4 × 20)/ 5 = 16 days.
∴ Time taken by B to complete the work is 16 days.