Unanswered Questions
61 questions with no upvoted or accepted answers
22
votes
0
answers
3k
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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
22
votes
0
answers
2k
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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 ...
- 197
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 ...
- 886
12
votes
0
answers
1k
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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 ...
- 336
11
votes
0
answers
406
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 ...
- 11k
9
votes
0
answers
476
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 ...
- 11k
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 ...
- 7,820
8
votes
0
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229
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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 ...
- 10.3k
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.
- 8,333
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
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 ...
- 1,006
6
votes
0
answers
536
views
What is a Sharp Number™?
This puzzle is based off and inspired by the What is a Word™ and What is a Phrase™ series started by JLee and their spin-off What is a Number™ series.
This was originally going to be a challenge for ...
- 210
6
votes
0
answers
511
views
Rare but Abundant in Hill and Hole
I am uncommon,
But a worthy goal.
Rare but abundant
In hill and hole.
Who am I?
You may already know the answer, so the task is not to answer the riddle per se, but to solve the following 'What is a ...
- 27.7k
6
votes
0
answers
186
views
How many items are there in the lab?
I am looking for how to complete the following question so that it gives a unique solution. Maybe somebody can give a visual solution.
A lab contains experimental equipment. 24 items are ready to use ...
- 117k
6
votes
0
answers
218
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What are the red, white, blue (and green) numbers?
Some numbers have been partitioned into $4$ groups. You must figure out how the numbers in each group are related, and what separates the groups.
Red: $1, 3, 4, 9, 13, 14, 15, 19$
White: $5, 7, 10, 12,...
- 148k