A can complete 2/3 of a work in 10 days and B can complete 4/5 of the same work in 8 days. They work together for 5 days. The remaining work is completed by C alone in 6 days. In how many days can C alone complete 75% of the same 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?