Ashish can do a piece of work in 30 days. He starts the work and continues for 5 days, then Bilal joins and together they work for 5 more days to complete the work. Find the time taken by Bilal to complete the work alone.
Answer & explanation
Correct answer: option 3
Ashish's work of 1 day = \(\frac{1}{30}\)
Work done in 5 days = \(\frac{5}{30}\) = \(\frac{1}{6}\)
Therefore, one - sixth of the work is done
Remaining work is done by Ashish and Bilal together in 5 days
Ashish and Bilal will complete the total work in 6 days
Efficiency of Bilal = 5 - 1 = 4
Time taken by Bilal alone to complete the work = \(\frac{Total\; work}{Efficiency}\)
= \(\frac{30}{4}\) = 7.5 days