X, Y and Z complete a work in 6 days. X or Y alone can do the same work in 16 days. In how many days can Z alone finish the same work?

A and B can complete a job in 24 days working together. A alone can complete it in 32 days. Both of them worked together for 8 days and then A left. The number of days B will take to complete the remaining job is:

If 36 farmers can do a piece of work in 24 hours, In how many hours will 18 farmers do it?

P and Q can complete a job in 24 days working together. P can alone complete it in 32 days. Both of them worked together for 8 days and then P left. The number of days Q will take to complete the remaining job is:

A can finish a work in 16 days and B can do same work in half the time taken by A. Then, working together, what part of same work they can finish in a day ?

A can complete a work in 16 days, working 6 hours a day. B can complete the same work in 12 days, working 9 hours a day. If both A and B work together, working 8 hours a day, in how many days can they complete the work?

P and Q can do work separately in 10 and 20 days, respectively. In how many days can they finish it, working together?