Unanswered Questions
142 questions with no upvoted or accepted answers
9
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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 ...
- 1
9
votes
0
answers
291
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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
9
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0
answers
489
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What causes these signs to follow this relation?
Can you find why does the below relation hold true?
Hint 1
Hint 2
- 3,943
8
votes
0
answers
452
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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, ...
- 400
8
votes
0
answers
277
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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
8
votes
0
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427
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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
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 ...
- 2,630
8
votes
0
answers
201
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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.
- 8,333
8
votes
0
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671
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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.
...
- 10.3k
7
votes
0
answers
197
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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 ...
- 7,820
7
votes
0
answers
314
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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 ...
- 6,581
7
votes
0
answers
397
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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 ...
- 1,006
7
votes
0
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486
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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.
"...
- 10.3k
7
votes
0
answers
14k
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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 ...
- 60.7k
6
votes
0
answers
255
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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):
...
- 2,423