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?

4 men and 6 women can complete a job in 8 days, while 3 men and 7 women can complete it in 10 days. In how many days will 10 women take to complete the same job?

The ratio of working efficiency of A and B is 4 : 5. If A alone completes the work in 15 days then in how many days can B alone complete the work ?

Rajan does $\frac{7}{11}$ of a work in 21 days. How many more days will he take to complete the work?

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?

A can do a work in 36 days, while B can do the same work in 48 days. If A works for x days while B works for x + 2 days, then one-third of the work is completed. Find the value of x?

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?