Though this puzzle is not à propos, it is fun, and has a lovely and simple solution. [Note! Click on the carpet to download a PDF version of the puzzle.] I hope that some of you enjoy it, and if it's not for you – pass it on!
The father of a friend of mine – a man I admired greatly - gave it to me about 35 years ago. It took me a while to solve, and I have passed it on to several people in the intervening years, but never heard if anyone solved it – though I did ask them to tell me. They may not have found it as interesting as I did, nor have had as much time on their hands as I did back then in my somewhat misguided youth. Or perhaps they thought it was too easy. Or maybe it didn't get solved...
Please, if you figure it out – do let me know.