A can do a certain work in 12 days. B is 60% more efficient than A. How many days does B alone take to do the same work?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → \(\frac{15}{2}\) days
For a fixed piece of work, time taken is inversely proportional to efficiency: a worker who does more work per day needs proportionately fewer days.
B is 60% more efficient than A, so B does 1.6 times as much work as A in a day
So B needs the time of A divided by 1.6: \(\displaystyle\frac{12}{1.6}=7.5=\frac{15}{2}\) days