Question : A, B and C can do a piece of work in 20 days, 30 days and 60 days respectively. If A works daily and on every third day B and C also work with A, then in how many days, will the work be completed?

Question : A, B and C can do a piece of work in 11 days, 20 days and 55 days respectively. How soon can the work be done if A works with B on the first day, A works with C on the second day and so on?

Question : A can do a piece of work in 25 days, and B can do the same in 30 days. They work together for 5 days, how much of the work is left?

Question : A can complete one-third of a work in 10 days and B can do $\frac{3}{5}$ th of the same work in 24 days. They worked together for 10 days. The remaining work was completed by C alone in 15 days. In how many days can C alone do $\frac{2}{3}$rd of the same work?

Question : A, B and C together can complete a work in 20 days. A and B together can complete the same work in 30 days. Then, C alone can complete the same work in how many days?