If 6 men and 8 boys can do a piece of work in 10 days while 26 men and 48 boys can do the same in 2 days, find the time taken by 15 men and 20 boys to complete the same type of work.

If P and Q together can complete a piece of work in 15 days and P alone can do it in 45 days, in how many days can Q alone complete that work?

A can lay a railway track between two stations in 16 days and B can do the same job in 12 days. With the help of C, they finished the job in 4 days. In how many days can C alone do the job?