JoeAnt.com Directory

Puzzles collected by Guy Kindler, most requiring some undergraduate mathematical knowledge. Some hints are provided.

http://campuscgi.princeton.edu/~mathclub/index.pl

Challenging puzzles, some requiring undergraduate mathematical knowledge. Full solutions are provided several weeks after each problem is set.

http://www.math.purdue.edu/academics/pow/

A collection of riddles, puzzles, and technical interview questions, with a discussion forum.

http://www.ocf.berkeley.edu/~wwu/riddles/intro.shtml

A collection of puzzles, with hints, solutions, and links to relevant mathematical topics.

http://www.qbyte.org/puzzles/