Unanswered Questions
84 questions with no upvoted or accepted answers
22
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0
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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 ...
- 660
14
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0
answers
1k
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12
votes
0
answers
454
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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 ...
- 16.2k
12
votes
0
answers
259
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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 ...
- 19.3k
12
votes
0
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896
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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 ...
- 886
10
votes
1
answer
752
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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 $a+b$ ...
CommunityBot
- 1
10
votes
0
answers
512
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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
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 ...
- 2,389
9
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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
votes
1
answer
2k
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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 ...
CommunityBot
- 1
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
answers
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
559
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
8
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0
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346
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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███████████████...
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