M alone can complete a work in 50 days and N alone can complete the same work in 100 days. If both of them work together, then in 25 days what percentage of the total work will be completed?

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?