Unanswered Questions
142 questions with no upvoted or accepted answers
32
votes
0
answers
3k
views
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, ...
25
votes
0
answers
2k
views
Decrypting the Key: "Phage is Spreading.."
I've been trying to solve this puzzle called "Phage is Spreading.."
...
22
votes
0
answers
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 ...
18
votes
0
answers
712
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:
...
14
votes
0
answers
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 ...
14
votes
0
answers
843
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?
14
votes
0
answers
1k
views
12
votes
0
answers
455
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
votes
0
answers
259
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 ...
12
votes
0
answers
896
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 ...
11
votes
0
answers
340
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 ...
10
votes
0
answers
714
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:
10
votes
1
answer
752
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 $a+b$ ...
10
votes
0
answers
512
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,
...
9
votes
0
answers
361
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 ...
9
votes
0
answers
693
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 ...
9
votes
0
answers
291
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 ...
9
votes
0
answers
489
views
What causes these signs to follow this relation?
Can you find why does the below relation hold true?
Hint 1
Hint 2
8
votes
0
answers
452
views
Cookie Unionization
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, ...
8
votes
0
answers
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 ...
8
votes
0
answers
427
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 ...
8
votes
0
answers
530
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 ...
8
votes
0
answers
201
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.
8
votes
0
answers
671
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.
...
7
votes
0
answers
197
views
Can you construct a nonagon with 47 rods?
Stiv's Diabolical Instruments now offers a bundle of exactly 47 equal-length rods that can be joined by hinges at their ends – and only the ends – to form planar linkages (i.e. all hinge axes are ...
7
votes
0
answers
314
views
Even and primes puzzle?
These are secret numbers that increase regularly. What are the next two numbers?
If you like numbers, it will be fun.
$2^3 \times224299$
$2^2 \times 3^2 \times 19 \times 3557$
$2 \times 5 \times ...
7
votes
0
answers
397
views
Open the French safe
While walking in a small alley in Paris, you come across a safe.
The number pad looks like this :
There are things on the back of the safe too :
"À l'aide du carré 3x3 ci-dessous et des nombres ...
7
votes
0
answers
486
views
A multi-symptom affliction
"Kindly state your name." The nurse's voice was polite, but qiet.
"I'm sorry, I can't hear you, my hearing's bad."
Being mostly deaf was quite frustrating for our patient.
"...
7
votes
0
answers
14k
views
Crypto Riddle for a bonus track
here is a crypto riddle a artist named Master Boot Record put on the page of his music.
087 104 101 110 032 116 104 101 032 077 111 111 110 032 119 105 108
108 032 115 104 101 100 032 110 111 032 108 ...
6
votes
0
answers
255
views
Visual puzzle involving mathematical operations
Try this puzzle. It involves mathematical operations. Created on my own.
CSV (for those who aren't able to see images):
...