Ramesh can do 20% more work as Mohan can do in same time. If Mohan can finish the work in 30 hours then Ramesh with the help of Mohan, can finish the same work in how many hours?
110/25 hours
150/11 hours
140/9 hours
130/12 hours
Solution
Mohan can complete a work in 30 hours.
Ramesh can do $\frac{6}{5}$ work in 30 hours.
So Ramesh can complete the work in $30\times \left( \frac{5}{6} \right)~=~25$ hours.
Together they can finish $\frac{1}{30}~+\frac{1}{25}$ of work in 1 hour i.e., $\frac{11}{150}.$
So in $\frac{150}{11}$ hours, they will finish the work together.