This is a fairly random collection of puzzles, mostly with a mathematical flavour. A few are original, but most are picked up from friends, books, newsgroups, etc. Some are credited [like this], but in many cases I'm afraid I've forgotten where they came from. Some aren't really puzzles, but just questions that happen to have caught my interest.
Many of them have a "spoiler" version giving the answer, or a partial answer, and usually some working. Except where credited most of the solutions are by me, in the sense that the working's mine even if they'd been solved by others before. This means there may well be errors in the working. The symbol ??? indicates a puzzle to (part of) which I don't know the answer. The notation MeN means M x 10N.
If you make any progress on any of these puzzles, or if you'd like to contribute a new one, then please do tell me about it.
This page is maintained by Thomas Bending,
and was last modified on 25 October 2017.
Comments, criticisms and suggestions are welcome. Copyright © Thomas Bending 2017.