A water tank can be filled in 36 minutes by using 45 pipes of the same capacity. In how many minutes (rounded off to two decimal places) will the water tank be filled if 37 pipes of the same capacity are used?

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?