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

1. 4x1/4 minutes
2. 3x3/5 minutes
3. 3x1/2 minutes
4. 1x1/2 minutes