Questions tagged [mathematics]
A puzzle related to mathematical facts and objects, whose solution needs mathematical arguments. General mathematics questions are off-topic but can be asked on Mathematics Stack Exchange.
5,584 questions
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How many guesses do you need at most to solve Mastermind variants?
My father likes to tell a story about how he broke the system for a game event his school held. Specifically, he figured out a way to always at least break even on the Mastermind-like game, which ...
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-4
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Make the numbers 45, 44, 43, 42, 41, and 40 out of the numbers 2 0/0! 2 6
0 can be either used as a 0 or a 1 with the symbol 0!. You can use concatenation, brackets, subtraction, multiplication, division, and addition. I got this sheet at school from my teacher.
using the ...
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Bridge building with irregular planks
Imagine you have a big rectangular pond in your back garden. You wish to build a bridge from your house in the lower left corner to the small pagoda in the top right.
You have lots of planks of ...
- 14.4k
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Cryptic skyline information
What information ? ? does the last skyline hold ?
if
/\ /\ /
/\/ \/ \/\/\/ = 2 ♡
and
/\ /\ /\
/\/\/ \/ \/ \ = 6 ♢
and
...
then
/\
/\/\/\/\/\/\/ \ = ? ?
...
- 14.4k
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20 people where each person bears a grudge against exactly one other person in the group
Here's a problem I recently saw (not my own):
In a group of 20 people, each person bears a grudge against exactly one other person in the group. No matter how these grudges are arranged (multiple ...
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-2
votes
1
answer
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Make the number 49 with the digits 2, 0, 2, 6
0 can be either used as a 0 or a 1 with the symbol 0! I got this sheet at school from my teacher. You can use brackets, subtraction, multiplication, division, and addition
using the digits in 2026 as ...
- 17
8
votes
1
answer
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Golden Burgers Assignment
A job with one instruction:
Deliver the package to Golden Burgers.
In full, please... the last courier took 11 bytes, leaving us with a nothing burger.
When you arrive, they'll ask for a password.
...
- 267
17
votes
2
answers
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Cover a cube with hugs and kisses!
The following set of eight shapes (which sort of looks like XOXOXOXO if you squint with your brain a little):
... can all be folded onto the surface of a single cube in a way that covers the entire ...
- 23.9k
11
votes
2
answers
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Origami Checkerboard
Prove using induction that, for all positive integers m and n, there exists large enough positive integers x and y such that you can fold a m × n paper with checkerboard patterns on at least one side ...
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What logical statement does this prove?
dnlem f = f (Right (f . Left))
What logical statement is being proven by the above line?
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Are you ready to Mingle?
Mingle is a game played in the television series Squid Game. 100 players enter the game arena. The game runs for 2 rounds. During each round r, the game host selects a number Nr, where 2 ≤ Nr ≤ 100. ...
- 14.4k
5
votes
4
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How do you produce the number 5, using only 3 eights?
How do you produce the number 5, using only 3 eights? The 4 operations (+ - x and division) + square root and factorial are allowed but no extra numbers (no squaring).
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6
votes
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Making an expression with the numbers 1 to 20, odd or even
The numbers 1 through 20 are written in a row. Two players take turns putting plus signs and minus signs in front of each number. So, a total of 20 signs are to be put in front of the numbers.
When ...
- 106
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votes
2
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Mermin's Lights Out
You're given a 3x3 square grid of lights. Initially, the three lights along the main diagonal are lit. You are allowed to do two types of toggling operations:
Toggle all lights along any row.
Toggle ...
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13
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2
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Is there a 6x6 magic square with distinct hexominoes?
The 6x6 magic square shown below has magic constant 2433. It is tiled with six distinct hexominoes in such a way that numbers inside every hexomino also sum to 2433. Unfortunately, this magic square ...
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