A and B can do a piece of work in 12 days and 15 days respectively. They started the work together, but after some days B left the job. A finished the remaining work alone in 3 days. If A and B are contracted to do this work for Rs. 6600, find B's share of the money.

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?