'A', 'B' and 'C' can finish a work in 8, 12 and 15 days, respectively. If they work together and complete the work, in what ratio should the money be shared between 'A', 'B' and 'C'?

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?