A can do a piece of work in 10 days while B alone can do it in 15 days . In how many days can both finish the same work?

A and B together can do a piece of work in 12 days, while B alone can finish it in 30 days. In how many days can A alone finish the work?

A alone can do a piece of work in 10 days and B alone can do it in 15 days. In how many days will A and B together do the same work?

A and B together can do a piece of work in 12 days, while B alone can finish it in 30 days. A alone can finish the work in

A can do a piece of work in 4 days and B can do it in 12 days. In how many days will they finish the work, both working together ?

A can do a piece of work in 14 days while B can do it in 28 days. In how many days, working together will they complete the whole work?