8 men and 13 women can complete a piece of work in 12 days, while 10 men and 14 women can complete the same work in 10 days. The daily work of how many women is equivalent to the daily work of one man?

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?