rec.puzzles Archive

1596 puzzles with solutions, arranged by subject. Search all titles · 1194 new and restored.

Categories

• Analysis44 +30
• Arithmetic161 +111
• Combinatorics66 +53
• Competition131 +103
• Cryptology13 +9
• Decision37 +35
• Geometry167 +126
• Group23 +3
• Induction10 +5
• Language435 +364
• Logic142 +103
• Magic6 +5
• Physics61 +52
• Pickover19 +3
• Probability108 +82
• Real-life14 +10
• References29 +27
• Series66 +21
• Treasure17 +16
• Trivia47 +36

See also

• Ask the rec.puzzles Oraclepuzzle questions answered from the archive, or by AI models with the editor's review
• Taxonomy of Wordplayword records
• Word Ways Challengesopen wordplay problems from 1979, with computer results

About the archive

Instructions for Accessing the rec.puzzles Archive

INTRODUCTION

The rec.puzzles Archive is a list of puzzles, categorized by subject
area.  Each puzzle includes a solution, compiled from various sources,
which is supposed to be definitive.  The latest version of the archive
is available on the Web at:

https://questrel.com/puzzles/


THE rec.puzzles ORACLE

The Oracle answers puzzle questions on the Web at:

https://questrel.com/oracle/

Type your question in full and press "Ask the Oracle".  The Oracle
first looks for your puzzle in the archive, and if an entry already
answers it, shows you that entry.  If not, several AI models each
answer the question, and one of them edits their answers into a draft
archive entry, which you can read on the page.  Questions are collected
every ten minutes, so an answer can take up to about a quarter of an
hour; leave the page open.  The answers are unreviewed and can be
wrong.  The editor reviews every draft, and approved entries join the
archive.  The Oracle does not accept questions by e-mail.


CREDIT

The archive is NOT the original work of the editor (just in case you were
wondering :^).

In keeping with the general net practice on FAQ's, I do not as a rule assign
credit for solutions.  There are many reasons for this:
1.  The archive is about the answers to the questions, not about assigning
    credit.
2.  Many people, in providing free answers to the net, do not have the time
    to cite their sources.
3.  I cut and paste freely from several people's solutions in most cases
    to come up with as complete an answer as possible.
4.  I use sources other than postings.
5.  I am neither qualified nor motivated to assign credit.

However, I do whenever possible put bibliographies in archive entries, and
I see the inclusion of the net addresses of interested parties as a
logical extension of this practice.  In particular, if you wrote a
program to solve a problem and posted the source code of the program,
you are presumed to be interested in corresponding with others about
the problem.  So, please let me know the entries you would like to be
listed in and I will be happy to oblige.

Address corrections or comments to archive-comment@questrel.com.