Closing the gap: solving puzzles
“The other day, I decided to cycle into town. When I looked at the bicycle, I noticed that one of the tyres was flat. Problem! A quick visual inspection showed nothing obviously wrong: no nails or pieces of glass puncturing the tyre. I took a chance, pumped up the tyre, noticed that it inflated and seemed to stay that way, and cycled successfully into town and back.
The next morning, I checked the tyre again. It was definitely softer than the day before, but not completely flat. A slow puncture, evidently. Only two probable causes: a hole in the inner tube or a leaky valve. I removed the tyre, extracted the inner tube, inflated it a little more and submerged it bit by bit in a bowl of water. In ...