'A' can do a piece of work in 24 days. If 'B' is 60% more efficient than 'A', then the number of days required by 'B' to do the same piece of work is:

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?