18 men can complete a job in 20 days. 16 women can complete the same job in 24 days. How long will it take for 5 men and 16 women working together to complete the job?

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?