Skip to main content. RSS What's this?  Nick's Mathematical
Puzzles  Welcome to my selection of mathematical puzzles.
What's new?  See puzzle 160.   Explaining how an answer is
arrived at is more important than the answer itself.  To this
end, hints, answers, and fully worked solutions are provided,
together with links to related mathematical topics.  Further
references are provided with many of the solutions.  The puzzles
are intended to be fun, with an educational element.  Each
puzzle is assigned a level of difficulty of between one and four
stars, with four being the most difficult.  Clearly this is to
some extent subjective, but it may be useful as a rough guide.
The source for each problem is given at the bottom of the
solution page.  I usually provide only a proximate credit; some
math puzzles have been around for so long it can be difficult to
trace their provenance.  However, if I know the original source,
such as when a puzzle is a recognized mathematical theorem, I
credit that source.  I welcome