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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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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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 ...
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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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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 ...
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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. ...
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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 ...
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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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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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Arrange 11 (or fewer) squares that will be colored
This puzzle is related to the Four Color Theorem.
Arrange 11 (or fewer) non-overlapping unit squares on the plane such that, for any coloring of these squares in three colors, there exist two ...
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A six-variable math-logic puzzle with a unique solution
My original puzzle: Six variables 𝐴,𝐵,𝐶,𝐷,𝐸,𝐹 are distinct integers from 1 to 10 (inclusive).
They satisfy the following conditions:
B - D = 2
F + A = 11
A is between D and C
No two ...
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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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A 5x5 magic square with pentominoes?
The image shows two ways to tile a 5x5 square with five distinct pentominoes.
Is it possible to fill one of these two tilings with integer numbers 1, 2, 3, ..., 24, 25 in such a way that the tiling ...
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Minimize the total cut length for a 7x8 rectangle
A 7x8 rectangle is cut from a sheet of graph paper. Cut this rectangle into polygons consisting of no more than 5 squares each in such a way that the total length of the cuts is minimized (the cuts ...
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A polynomial with some integer values
Let $f$ be a polynomial with complex coefficients and $n\in\mathbb N$ such that
$\deg(f)\leq n$
$f(0), f(1),...,f(n)\in\mathbb Z$
Prove or disprove each of the statements
$f(\mathbb Z)\subseteq\...
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