A man can do a piece of workin 30 hours. If he works with his son then the same piece of work is finished in 20 hours. If the son works alone he can do the work in
Given that man can do a work in 30Â hr
In 1hr, work done by Man = $$\frac{1}{30} $$
Along with Son, Man can do work in 20 hr
In 1hr, work done by Man and Son = $$\frac{1}{20} $$
=> In 1hr, work done by son = $$ \frac{1}{20} - \frac{1}{30} $$
=> work done by son in 1hr =Â $$ \frac{1}{60} $$
Therefore, son takes 60hr to complete the work.
Create a FREE account and get: