Atul and Vignesh can complete a job in 10 and 12 days, respectively, if they work separately. In how many days will the job get completed if Vignesh starts the work and they work on alternate days on the same 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?