10. Five marks exercise problems V

\(A\) can do a work in \(45\) days. He works at it for \(15\) days and then, \(B\) alone finishes the remaining work in \(24\) days. Find the time taken to complete \(80\%\) of the work, if they work together.

 

Time taken to complete \(80\%\) of the work \(=\)  days