Ankita can write a manuscript in 20 days. Ankita, along with her friend Somya, can write the manuscript in 12 days. In how many days can Somya alone write the manuscript?

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?