X persons can complete a work in Y days. Then, 3X persons can complete the same work in ……….. Days and `(x)/(3)` persons can complete the same work in …………….. Days.

12 persons can complete half of a work in 9 days. How many persons can complete the same work (whole) in 6 days?

A and C together can complete a work in 120 days, C and E together can complete the same work in 80 days and A and E together can complete the same work in 160 days. In how many days A, C and E together can complete the same work?

C alone can complete a work in 20 days and D alone can complete the same workin 30 days. In how many days C and D together can complete the same work?

X, Y and Z together can complete a work in 20 days. Y and Z can complete the same work in 30 days. In how many days X alone can complete the same work?

If 10 men can complete a work in 12 days . In how many days can 18 men complete the same work ?

A alone can complete a work in 6 days and B alone can complete the same work in 8 days. In how many days both A and B together can complete the same work?