# All Questions

380 questions with no upvoted or accepted answers
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### Noita Eye Glyphs

A puzzle found hidden between the background layers of the computer game Noita. The puzzle has not been solved since it was added to the game in October of 2020. It is made of thousands of eye images, ...
• 6,832
2k views

### Is there a move-efficient way to rotate the center pieces on the Octo-Star?

I'm looking for a more efficient algorithm to rotate the center column of the Octo-Star puzzle 45 degrees. The situation below occurs when four properly-oriented edges are next to each other, ...
2k views

### Decrypting the Key: "Phage is Spreading.."

I've been trying to solve this puzzle called "Phage is Spreading.." ...
3k views

### What does this mathematical operator do?

The solution to this puzzle is one I came up with when working on this puzzle: What is the answer of this math puzzle? For two natural numbers a,b, can you figure ...
• 612
2k views

### REALLY important days in history

@Z. Dailey asks a mathematical puzzle Important days in history... and to come! with a series of dates in years 1973, 1978, 1983, 1992, 2005. My puzzle asks the question: What is the previous date in ...
• 11.7k
967 views

### Alternate, complex potions puzzle from HP fanfic

A long narrow room. The entrance is blocked by purple flame, the path onward blocked by black flame. On a table, the only thing in the room, are two dozen potions in opaque bottles. Half green glass, ...
• 191
699 views

### Determining the meaning of a challenge coin

I saw this rather cool looking challenge coin the other day, and I was wondering what the associated binary on the back of it means, as it isn't standard ASCII. In plaintext: ...
• 281
650 views

### Qubes: Oh, For the Love Of

TL;DR: This is a mixture between a tribute/spin-off puzzle and an attempt at a new puzzle type, greatly inspired by the notorious arcade game, Q*bert, published originally by Gottlieb Amusement Games. ...
• 793
2k views

### Crack the pigeon code

Can you crack this message? It was discovered in a chimney in 2012 attached to a carrier pigeon and was most likely sent during the D-day invasions. The GCHQ was not able to crack it, even after ...
824 views

### Grandma's keynote

Found this note which is addressed To my grandma, in her chest Since she's passed now, here's my quest.. What tickled her interest? And who invited her as guest?
• 2,565
1k views

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383 views

### Can we find four identically colored numbers?

Take the positive integers {1, 2, 3, ...} and color them red, green or blue. Is it true that no matter what coloring is chosen, we can always find three distinct numbers x, y and z so that x, y, z ...
• 12.1k
246 views

### The Snake and the Hunter

The Snake and the Hunter is a game for two players who play in two rounds interchanging the roles of snake and hunter. The game is played in a rectangular grid of points, say 6×6. In both rounds the ...
887 views

### Dissecting a figure into 2, 3, 4, and 5 parts but not 6

This figure is divided in 2, 3 and 4 equal parts of same size and shape, but it is not possible to do it in 5 equal parts of same size and shape. Is it possible to find a figure that can be divided ...
1k views

### Hidden message in rap text II: "Ya, a ray 'ave july joy!"

This puzzle is inspired by this one by @LukasRotter. Hopefully you don't mind me using similar (well, basically the same) format as yours, Mr. Rotter! ;) The same rapper released another teaser for ...
• 1,746
605 views

### Found the key, but what to unlock?

Here's a series of text messages between me and my friend. Me: Couldn't use ebg13, so used ______ to hide my messages. Him: What? How is this possible??? Me: A big prime ______, what else did you ...
• 748
469 views

### Quantum tic tac toe strategy

Most of us learn tic tac toe early in our life. Also, it is easy to find an optimal strategy for playing. How about Quantum tic tac toe? What is the optimal strategy for playing it? Rules On a ...
• 4,585
742 views

### Meteor strikes again

Part of a phone call: -...well why didn't you just say so? -It wasn't as easy as you thought, Jack. All the power lines here were destro--- -I know...It's not like we're living on a different planet ...
338 views

### Can you find the cipher that I used?

I have encoded a phrase, using a cipher that I invented. But I don't want you to decode it, rather I want you to figure out how my cipher works. This is the phrase that I encrypted Find the ...
• 161
337 views

### The Majestic but Draconian Dinner

We are hosting a dinner party. Here is a list of things you can take: Hotdog Grapefruit Oreos Potato Salad Cheetos Utensils Katlyn Predator Drones Banana However,...
• 2,260
327 views

### An Attempt at AV Puzzle

Here's another puzzle with visuals and sound. I hope you enjoy it! With Sound: https://youtu.be/yHkQdEu0QpA Static Image (the musical notes represent the music in the YouTube video): Hint 1 Hint 2
• 812
403 views

### What is a Freecell 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 Freecell Word™. Use the ...
• 5,190
514 views

### April Fool's Enigma

Every year, a famous French youtuber (e-penser) presents his enigma of April Fool, but this year, targeting specifically a group of people who have done particularly well last year, he raised the ...
• 1,257
701 views

### A funny looking cipher puzzle

What secrets does this jester hold? Hints are found down the road. A hint, or rather, that what is held transcribed:
745 views

### Powerful number systems

Imagine I have two positive integers, $a$ and $b$. Can you find the last digit of the sum $a+b$ given only the last digits of $a$ and $b$? More generally, can you find the last $n$ digits of $a+b$ ...
• 461
506 views

### I'm a number with a special product, so name me when you think you've got it

In the blocks that come before, their special product tells us more. To guess my scheme you'll need calculation, but only little tests of recreation. Each block contains atoms strong as Thor, ...
• 2,296
2k views

### 3D ring/rope wooden puzzle solution?

I have a Eureka 3d "Puzzle G":* The box lists 3 puzzles: Remove the ring Remove the rope Move the ring to the other side While I was able to solve shows the first puzzle, I haven't ...
• 406
304 views

### Dreamcatcher Puzzle

I created this puzzle as part of a set of puzzles about good wishes for a wedding. Does it work?
• 252
668 views

### A nice riley, hopefully is fun

Within these lines is a puzzle I've made. With cunning and wit, can you guess my trade? Inside the tome of the element's power, One minute per side, you'll read for an hour. A single number of the ...
348 views

### 12:41 puzzle: colorful geometry

The answer is a 4-letter word. I will not be giving any hints. This puzzle is very old. The puzzle is solved using only the image (no clues to the puzzle in title or description).
357 views

### A Glutton and a Split Check

N, T, A, B are arbitrary constants in this problem. I have only definitively solved the N=1 subproblem, so, if the general problem cannot be solved, I will be satisfied to mark as accepted a solution ...
• 2,389
286 views

### Rolling dice in a box

A box containing identical dice that were arranged to have same orientation has a missing die at the center (see figure). The dice moves to the free space for they can change orientation and ...
• 6,656
686 views

### Signatures of serial killer Edward Wayne Edwards?

This is from a real-life murder-mystery. In 2009 Edward Wayne Edwards was arrested and convicted of five murders, following a tip-off from his daughter April. Former detective John A. Cameron ...
474 views

### The highest poem

I am three, often a person, always a digit, and also witout. George POUST was his name. Manufactured by Ford between 1972 and 1976. YMCA was not my first team in my coaching career. Theory of ...
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289 views

### Zed's Order: Breakfast at Elon's

My friend Elon and I constantly irritate each other. He recently built himself a rather respectable restaurant – a sort of bed-&-breakfast, minus the beds. Last week, he asked if I could ...
• 793
488 views

### What causes these signs to follow this relation?

Can you find why does the below relation hold true? Hint 1 Hint 2
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364 views

### My drunken formula?

I know that today is an important day, but I can't remember why... All I have in my possession is this formula I wrote last night in my drunken stupor: You go here: B = 25 + \biggl(\frac{O}{...
• 10.6k
2k views

### Is there another name for this puzzle? (Kyudoku, Nine Find)

Is there another name for this type of puzzle? I can only find two examples of it online: https://www.brainzilla.com/logic/kyudoku/ http://ninefind.com/ In the game you start with a 6x6 grid filled ...
• 91
448 views

My Christmas cookies are gone! When I came into the kitchen this morning, the box was empty. All that remained were a few crumbs and this note: We absconded. You never saw that coming, did you? Well, ...
• 400
277 views

### Doubling the cube with rational Meccano strips

In three monographs published in 2006, 2008 and 2014 Gerard 't Hooft considered "Meccano mathematics": how to construct specified distances and regular polygons by a rigid system of ideal ...
• 7,820
618 views

### Connect The Wall-Words:

We have a group of 16 words here: ACIDITY TIME MICROSCOPE MARKS LIGHT SCALE CHEMISTRY CLAW REAL LEAD INTEREST BIOLOGY DUCK RADICAL ACADEMY LEAF Goal: Group these $16$ words into $4$ groups, each ...
• 1,754
423 views

### An Evil Cartesian Psycho

I came up with this puzzle when I was in high school. There is an island owned by an evil man who keeps some tourists who were visiting the island a few years ago captive. The authorities demanded ...
• 2,272
226 views

### There are 49 cards here. Figure out what the seven facedown cards are and what position they're in

So here's the problem "There are 49 cards here. Can you figure out what the seven facedown cards are and what position they're in?" I have tried about everything in my math tool belt to try ...
554 views

### Ode to a Nightingale: a puzzling study in literary criticism

The field of literary criticism is an interesting and fruitful one, in which puzzlers might carve out a niche. This was recently brought home by a conversation I had with a sagacious old gentleman in ...
• 5,430
529 views

### Impossible Cipher v1.0

When I create riddles, ciphers etc.. they seem to get solved within only a couple of days of writing. Well no more! This cipher may not be impossible but is extremely difficult. If left unsolved for ...
• 2,630
341 views

### We found text from the year 2040!

Recently, the first surviving examples of text from the ███████████████e discovered! The unearthed artifacts included a collection of rectangular tablets inscribed in the hitherto unknow███████████████...
• 181
198 views

### Is it possible to create a knot that is locked only when the rope is stretched?

Is it possible to create a knot that is stable/locked when the rope is stretched? When the tension is relived the knot should open.
• 273
670 views

### How to Complete this Cryptographic Challenge?

This question is from a CTF that a company (EY Cybersecurity) did almost a year ago. The original website is no longer available. ...
165 views

### Logic and geometry problem 2

My question is whether or not a deadlock can occur in Crisscross. A deadlock is defined as a position, an arrangement of checkers, in which the board has been filled but neither player has won. ...
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