A piece of work can be completed by 18 women in 10 days. After working together for 4 days, 6 women leave the job. How many more days will the remaining women take to complete the remaining work?

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?