A is 20% more efficient than B.B can do a piece of work in 20 days. In how many days can A do the same work?

A can do a piece of work in 16 days and B can do the same work in 20 days.In how many days can they do the same work,working together?

A is 20% more efficient than B. If B alone can complete a piece of work in 12 days, then A alone can complete the same work in how many days?

A can do (1)/(10) th of a piece of work in a day. B can do the same work in 15 days. In how many days can they do the same work, working together?