A can do a certain work in 12 days. B is 60% more efficient than A. How many days does B alone take to do the same work ?

A tyre has two punctures. The first puncture alone would have made the tyre flat in 6 minutes and the second alone would have done it in 9 minutes. If air leaks out at a constant rate, how long does it take both the punctures together to make it flat?

X is twice as good a workman as Y and together they finish a piece of work in 18 days. In how many days will X alone finish the work?

Neha can complete a work in 6 days and Ishrat can complete the same work in 4 days. What will be the time taken by them to complete the same work together ?

A and B together can complete a work in 12 days. A alone can complete it in 20 days. If B does the work only for half a day daily, then in how many days A and B together will complete the work?

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 ?

P can complete a work in 20 days while Q is 25% more effiecent than P. Q worked for 6 days and left, remaining work is completed by R in 15 days. Find in how many days R can complete the whole work alone?