66 votes
Accepted

I have forgotten what the puzzle was

I am ashamed this came to me so quickly.
Neil W's user avatar
  • 2,288
24 votes
Accepted

What is the name (and brand / year) of this puzzle?

After searching around, going through Hungarian Rings, I finally stumbled on Radosza's Rings, which seem to be educational toys. Link
JonTheMon's user avatar
  • 9,890
22 votes

How can a logic puzzle be defined?

I think the most-common definition of a logic puzzle is one that requires the solver to make deductions using formal logic, like the famous Einstein's puzzle. With this type of puzzle, you use only ...
GentlePurpleRain's user avatar
16 votes
Accepted

How can a logic puzzle be defined?

Borrowing language from fuzzy set theory, what you have is a crisp, binary decision imposed on a set of more than 2 values, at least one of which is fuzzy. Let me explain. Your friends implicitly ...
Lawrence's user avatar
  • 7,909
15 votes

The origin of the blue eyes puzzle

For the muddy children variant of this problem, there are several earlier sources. For instance, A.A. Bennett (Problem No. 3734, American Mathematical Monthly 42, 1935, page 256) formulated the ...
Gamow's user avatar
  • 45.5k
15 votes

Looking to find the name and objective of this puzzle

Looks very similar to Simon Tatham's "Net". The goal is to get everything connected together; the operation you're allowed to do is to rotate each square by any multiple of 90 degrees.
Gareth McCaughan's user avatar
14 votes
Accepted

Single letter chemical elements on a 2x2 grid

The answer is: First row: Second row: The elements are:
GoodDeeds's user avatar
  • 913
13 votes

A riddle in James Still's "River of Earth"

My guess would be Explanation: First green and then yeller, (sic. yellow) All guts and no tallow.
gstats's user avatar
  • 1,110
13 votes

Puzzle similar to 15-puzzle but more moveable pieces?

As answered by @BeastlyGerbil, you have the world of twisty puzzles. Here in the Twisty Puzzle Museum you can find over 5,000 of these kind of puzzles, and here is my personal collection of currently ...
Kevin Cruijssen's user avatar
13 votes
Accepted

14 piece wooden cube puzzle

This type of puzzle is called a burr puzzle. This particular one was designed by Bill Cutler, and is called Wausau '83. It is produced by Jerry McFarland, and available from Bill himself, or from Mr ...
Jaap Scherphuis's user avatar
12 votes

Puzzle similar to 15-puzzle but more moveable pieces?

Kevin Cruijssen gives some good examples. You might also want to consider multiple layers as a part of the puzzle, which allows you to have additional constraints, either visible or hidden. For ...
bkuehner's user avatar
  • 446
11 votes
Accepted

What is the name of AB×B×A=BBB puzzles?

This is a type of puzzle called a "cryptarithm" or an "alphametic". We have many examples of this type of puzzle under the alphametic tag.
Deusovi's user avatar
  • 146k
11 votes
Accepted

Twisty puzzle composed of hexagonal prisms, with As and diamonds

It was first released in June 2004 by Mefferts under the name Jackpot, and later it was renamed Platypus, and after that the New Generation Puzzle. It probably was sold under other names as well. See ...
Jaap Scherphuis's user avatar
10 votes

The origin of the blue eyes puzzle

The earliest occurrence of the puzzle that I am aware of is from 1958. George Gamow and Marvin Stern: "Puzzle Math", Viking Press (February 7, 1958) Here is the Amazon page for this book: http://...
Gamow's user avatar
  • 45.5k
10 votes
Accepted

The case of the world’s easiest puzzles

Possible answers for the non starred ones: a. You b. So c. So d. e. f So g So Now for the starred ones: h It was actually: i It was actually: j Or (thanks @Silenus) It was ...
Beastly Gerbil's user avatar
9 votes

What is the name of this mechanical puzzle with two G-like hooks interlocked?

After much scrolling, I found this puzzle on Rob's puzzle page, which lists hundreds of entanglement puzzles. It's a great page, definitely consider checking it out. This puzzle is from the (now ...
isaacg's user avatar
  • 5,807
9 votes

What kind of puzzle is this?

I've seen this be called "Mazes With Rules" or "Logic Mazes" see: https://www.logicmazes.com/dec99.html for Robert Abbot's take on the term, and if you want more of them he's ...
Spencer Fleming's user avatar
8 votes

3-sided pyramid with 9 red and white triangular pieces on each side

The Great Pyramid by Eliot Inventions Ltd I do not know whether the competition was won. The prize was not a million pounds - you may be confusing this with the Eternity puzzle that had such a prize ...
Jaap Scherphuis's user avatar
8 votes

The origin of the blue eyes puzzle

A version of this puzzle, involving three ladies with dirty faces laughing at one another, appears in J. E. Littlewood's "A Mathematician's Miscellany," published in 1953. Littlewood writes that this ...
Julian Rosen's user avatar
  • 14.2k
8 votes

Puzzle similar to 15-puzzle but more moveable pieces?

I'm sure you know of the Rubik's Cube. That has got multiple movable pieces. If you want something with a lot more movable pieces you could try some of the family members of the Rubik's Cube. For ...
Beastly Gerbil's user avatar
8 votes

Calculating with Symbols

These are usually called alphametics, but these usually have letters instead of numbers. A common example is below: \begin{align} &SEND\\ +&MORE\\\hline M&ONEY \end{align} The equivalent ...
boboquack's user avatar
  • 21.9k
8 votes
Accepted

What is this puzzle called? Have you seen it before?

Every instance of this type mentioned here, including the USAMTS problem and your screenshot, was written by me. You can also see my contributions GM puzzles, which is the best place to go if you're ...
Palmer Mebane's user avatar
8 votes

Mechanical puzzle ID: Ring, barbell, and four-holed panel

I haven't seen this particular puzzle before, but this seems to work: (Edit note: my earlier answer went through an extra loop, which turned the whole method into a complicated no-op. This new one ...
Bass's user avatar
  • 77.2k
8 votes
Accepted

Metal entanglement puzzle with an S-shaped piece, chain, and rings

I think the objective is to separate the small ring from the chain. Also, it seems the chain goes around the S-shaped part twice. This procedure removes one of those loops, so you'll want to repeat it ...
Bass's user avatar
  • 77.2k
8 votes
Accepted

What is the name & solution for this 33-piece 3D wooden puzzle?

This appears to be the Hercules burr puzzle. (It may also be known as Diamond #33; I can't tell if theirs is the same, because they claim to have 9 different shapes but they also don't cut the corners....
Deusovi's user avatar
  • 146k
7 votes
Accepted

What is the difference between enigma puzzle and cryptograms?

A cryptogram is a puzzle where letters are replaced by some other symbols in a one-to-one cipher. The most common type involves letters being replaced with other letters, but numbers and symbols are ...
Deusovi's user avatar
  • 146k
7 votes

The case of the world’s easiest puzzles

OK. Let's get the ball rolling. This was too fun to not come up with a fun alternative answer. So let's pretend I'm a contestant for Jeopardy. Me: "Alex, I'll pick puzzle identification for 1000". ...
Marius's user avatar
  • 18k
7 votes

The case of the world’s easiest puzzles

a. b. d. e. g. h. (but not e.) i. j.
KeyboardWielder's user avatar

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