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135 views

Ammann chair tiling puzzle

The Amman chair is an interesting shape that can be dissected in two pieces that are smaller copies of the original. The sizes of the two pieces are different. The ratio between the areas of the ...
2k views

When I am by myself, I am negative

When I am by myself, I'm negative. Give me 2, and I'll read the same. But if you halve me, I always seem surprised. Tack on a cliff, and I become smarter. A dreaded word I am... What am I? The answer ...
326 views

Encrypted fruits

Haven't been making a puzzle for a long time, this is a simple puzzle: figure the fruits with the given clues. 🚫 b->a,aeiou->? A 3-3 $[3,\infty)$ ✋-i 🤔 Tesla $^{12}X$ 🏃 $\boxed{^{4}}$ (🏞️ - ...
551 views

Dastardly Diagrams

I recently found this diagram taped over an image in my English textbook. We got it second-hand, so I assume that it must have been a little puzzle from the previous owner. It came with two questions ...
180 views

Unusual sequence of fractions

Let's have the following sequence of fractions: $\frac{156}{51}, \frac{756}{251}, \frac{3756}{1251}, ?$ . What fraction replaces the question mark?
324 views

A Puzzling Playlist

My friend loves puzzles, and one day I walked into her room while she was listening to music. I asked what she was listening to, and she listed off the albums in her playlist: Accustomed to Nothing - ...
121 views

A hacker emailed someone then

A hacker sent a message in to someone that says... DARKGREEN WHITE WHITE TURQUOISE He sent another one which is... Think you can keep up with me? Enemies inbound! "Stretch out your neck!"...
164 views

Wooden puzzle/game - 16 dowels with five wooden balls with holes each

I acquired a wooden puzzle game from a local thrift store. They had no information about it. Here's a description: In a wooden board base are mounted 16 dowels on each of the dowels are 5 wooden balls ...
412 views

A circle touches two sides of a triangle and two of its medians

A circle touches two sides of a triangle and two of its medians. Prove that the triangle is isosceles. This problem came from the Mathematical Digest issue 62 (Jan 1986) which in turn cited a Russian ...
64 views

Sequence of boxes with a rotating arrow, large (un)shaded circles in the corners, and a small circle [closed]

What is the next image? The small circle seems to follow the arrow, which would eliminate C and E.
156 views

What set is the odd-one out?

RCTPS MNCFON RCTPS KVWP BIBI HWQB IHQB IHQB ABAABBBB ABAAAABB ABAABBAB AABAAAAA ABAABABB ABAAABAB ABABAAAA ABABABBB AABAAAAA ABAABBAA ABAAABAA ABAAABBB ABAAABAA ABABAABB AABAAAAA ABAAABAB ABABAAAA ...
156 views

How many L-shaped pieces will not be used to make cubes?

The puzzle is as follows: The figure from below belongs to a didactical toy which is comprised of 32 congruent wood pieces as indicated in the figure. Each piece is made up by three cubes whose edges ...
136 views

What is the perimeter of a pentomino which can tile this heart-shaped board?

The puzzle is as follows: The figure from below shows a board that is made up of 30 squares whose sides are of 2 centimeters each. Such board must be split in six congruent pieces. These must be made ...
706 views

Fountain of Wealth

Based on the following crossword, find a word to describe those with fancy titles and lots of money. Across Down 1. Clear area for brightest star in constellation (6) 1. Refuse time off once at ...
629 views

This is a follow-up to (Almost) all hands on check by @loopy walt. The task (mate in one with as many essential pieces as possible) stays the same, but you are to go about it more cunningly. Recap of ...
77 views

Minimize cuts to an object to obtain weights which can be used to measure 1-40kg

The problem is as follows: Rick has a small store and a two pan scale which allows him to weight the coffee he sells. Certain day he forgotten the weights that he uses in his truck, however in his ...
101 views

Filling a 26x36 grid with trominoes

Let's have 312 L-trominoes of three different colors, 104 trominoes of each color. Can you fill a 26x36 grid with these trominoes without two of the same colors touching side-to-side anywhere? In ...
670 views

What is a Surprising Country?

If a country conforms to a special rule, I call it a Surprising Country. If it does not conform to this rule, I call it an Unsurprising Country. Here is a list (not exhaustive) of some Surprising ...
119 views

Join neckles to make one [closed]

Join five three-link chains to one 15-link chain To join two chains, you must cut, and then re-weld, a link. The new chain should have exactly two ends (no more, no less). The questions is what is ...
2k views

How can you get 13 pounds of coffee by using all three weights each trial?

The puzzle is as follows [with minor copy edits for grammar]: A merchant has a kiosk nearby our market. He has a sack of 52 pounds of coffee to sell. Assuming that he only uses a two pan scale and ...
374 views

Maximum number of masses you can weigh given 3 weights

The puzzle is as follows: Assume that you have a two pan scale and three weights, one of 1 pound, the other 3 pounds and the last one 9 pounds. In only one weighing trial, how many objects of ...
61 views

How can you use a two pan scale to find which coin is counterfeited? [duplicate]

The puzzle is as follows: Detective Mike has four bags with 100 coins of one cent each. All of these coins have the weight with the exception of one coin which weighs a little less than the rest ...
91 views

How many figures to cover the kitchen floor?

The puzzle is as follows: Figure 1.1 shows a kitchen floor that is made up of 30 squares whose sides measure 1 cm in length and in Figure 1.2 a tile that is made up of 5 squares whose sides also ...
70 views

How many figures are needed to cover all the star?

The puzzle is as follows: Figure 1.1 and Figure 1.2 shown are made up of congruent triangles. Assuming you must place tiles congruent to figure 1.2 to cover all the triangles in figure 1.1, without ...
662 views

Balancing the marble game (Red marbles are OP, please nerf)

Ash and Bree are playing a simple game of chance: They fill a bag with small marbles coloured red or blue. They take turns to draw a marble from the bag without looking, then: If Ash draws a red ...
1k views

Can I have a 'P' please, Bob?

An entry in Fortnightly Topic Challenge #51: Non-rectangular grids. For the avoidance of doubt, while the puzzle set-up is based on a real quiz show, the exact scenario described here is entirely ...
256 views

Arrange candies without repeating pattern

The following puzzle had been posted before but I couldn't understand the only answer that was given there, which was by @neodne . So, I created this post asking someone to explain neodne's answer to ...
163 views

Ifz, ipx bsf zpv epjoh Wbooz? What does this code from my mother's highschool stuff say?

I found this code in my mother's box of highschool stuff when we were cleaning the basement and found this just wondering what it says Ifz, ipx bsf zpv epjoh Wbooz? J bn epjoh xfmm, zpv? J bn epjoh ...
289 views

The Vowelburger™ Incident

Inspired by Avi's Vowelburger™ Riddle Last week, after English class at school, a few friends and I went to the local Vowelburger™ to get some lunch. Feeling hungry, we decided to order 13 burgers ...
3k views

What is a Jeeves Word™?

This is in the spirit of the What is a Word/Phrase™ series started by JLee with a special brand of Phrase™ and Word™ puzzles. If a word conforms to a special rule, I call it a Jeeves Word™. Use the ...
955 views

(Almost) all hands on check

Historical note (skip if you like): In this interesting puzzle @TSLF asks for the "maximum number of black and white pieces that are involved in a checkmate position". Originally, they left ...
114 views

Another prefix suffix puzzle

My start is teasing someone, My infix is a time unit, which means a lot of years ago, but without the y. My end is Peter Senerchia. My whole means dazzle.
328 views

AnaCross: A crossword made of anagrams

This is a new type of puzzle I've devised: the AnaCross. Nothing new under the sun and all, I'm sure someone has made one before, but I've never seen it. The rules are pretty simple. At the end of ...
248 views

Were the Decipher II and Decipher III puzzles solved, and if so when and by whom?

The Decipher jigsaw was a relatively famous puzzle released in the early 80s, promising a \$100,000 dollar prize to those that could solve it. After two years with no winners, the creator, Warren ...
107 views

My prefix has wild animals

Can you find out a word that has these following rules: -My prefix has alot of wild animals, -My infix has a heavy demand, -My suffix always questions themself, -My whole has a word in the meaning ...
140 views

What is the date displayed for the question mark?

Someone sent me these images. It's about the Moon for some reason. Anyways, here are the images: And also that someone gave me a bonus:
191 views

This ᴀɴᴅ That musical act from the past [closed]

Below is a fill-in-the-blanks three-part list of variously-venerable musical acts of the form “________ ᴀɴᴅ ʜɪs/ᴏᴜʀ/ᴛʜᴇ _________.” The example of “Paul Revere ᴀɴᴅ ᴛʜᴇ Raiders” has been filled in for ...
352 views

Checkmate in Last Move

What is the maximum number of black and white pieces that are involved in a checkmate position? That is, if any piece were removed from the board, the position would not be checkmate because that ...
116 views

A math sequence, but also a English sequence!

What are the numbers in the question marks? 0, 1, 2, ?, 5, 6, 8, ?, 40, 46, 60, ?, 84
228 views

Not a Fibonacci sequence

What is the next term in the sequence? 1, 1, 2, 3, 5, 8, 18, 34, 60, 120, 214, 394, 788 hints: #1
444 views

Only kings and horses

This is the fourth entry in my decentralised or "Swiss" chess mini series. See bottom for a recap of the modified rules of Swiss chess. Enough warm up! It is time for a proper Swiss chess ...
213 views

Fools in Switzerland

This is the third question of my mini series on decentralised chess, or Swiss chess. In Swiss chess, the advantage in terms of mobility of a centrally placed piece over a piece in the corner is ...
986 views

This escape room was terrible! Did I do something wrong?

Someone told me that I should put a link to Fortnightly Topic Challenge #50: Escape Rooms... whatever that is, sure. PSE, I need your help. I just got back from the worst escape room experience I've ...
115 views

Probability of a successful DT Cannon

In multiplayer Tetris, there are a number of opening setups that let you send powerful attacks very quickly. One popular opening is the DT Cannon, which allows the player to very quickly send a T-Spin ...
126 views

Four-Number Door Puzzle

So I had an idea for a number-based door puzzle for a TTRPG campaign that could readjust itself every time a wrong guess is made. Here's the basic premise: Given two numbers, find two more numbers in ...
2k views

Dirac notation for English

Dirac notation is very expressive: not only does it allow to write quantum states and operations more concisely, it can also be used to shorten written English words and phrases! Here are some ...
198 views

Pirates dividing booty around a circular table

A group of pirates have plundered one of his majesty's cargo ships and they all carried as much gold coins as each one could find. When they get back to their ship, they sit at a round table and pass ...
188 views

The Last Challenge

This question is a continuation of this one, and you might want to read it if you haven't already. 'Another code-name,' I think. 'There's no way that's his real name'. Nonetheless, I type in '...