A men can do a piece of work in B days and B women can do the same work in 2A days. If 10 men and 8 women can do the work in 6 days, then find the time taken by 7 men and 10 women to complete the entire 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?