A can complete a work in 30 days and B can do the same work in half the time taken by A. Working together what part of the work will they complete in 5 days?
Answer & explanation
Correct answer: option 4
Time ∝ \(\frac{1}{efficiency}\)
Ratio is reverse for time taken and efficiency
A : B
time 2 : 1
Eff. 1 : 2 total efficiency = 3
Let us say, total work be 30
so, time taken together = \(\frac{Total\; work}{Efficiency}\)
= \(\frac{30}{3}\) = 10 days
Therefore, in 5 days \(\frac{1}{2}\) of the work will be completed