Mathematics Stack Exchange
Mathematics Stack Exchange

Questions tagged [puzzle]

For questions about the mathematical principles behind puzzle, games, riddles, or their possible solutions. Questions that are not strictly mathematical in nature should be asked on Puzzling Stack Exchange.

Many puzzles, games, and riddles are based on mathematical concepts. This tag is for questions that ask about the mathematics behind a puzzle, game, or riddle, or about the solutions to mathematical puzzles.

If you already know the answer to the puzzle you are posting, you might consider posting your question on Puzzling Stack Exchange, instead. If you do end up posting your question on Mathematics Stack Exchange (MSE), please read the following meta posts on these kinds of questions before asking your question:

If you do end up posting on MSE, please make it clear in your question that you are "puzzling" the community and that you will be answer the question yourself if no one in the community posts your desired solution.

3301 questions
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Mathematical way to solve Honeycomb Puzzle

There is a puzzle: "Fill the board with letters from A to G, that in the field and in its surrounding each letter is placed only once (can't be repeated). This rule concerns also fields with not full surrounding e.g. edge fields. Could you tell me…
Jacek
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Simple Logical reasoning question

I am trying to improve my logical reasoning skills. Came across below question. See image. Can anybody let me know what the logical reasoning to the answer will be. I have no idea how to solve this The question is, "Which of diagrams A, B, C, D, or…
Programmer
  • 233
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How many points are there on the globe where by walking one mile south, one mile east and one mile north you reach the place where you started?

How many points are there on the globe where by walking one mile south, one mile east and one mile north you reach the place where you started?
Bharad Waj
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Alternative solution and generalization to a puzzle "gasoline crisis".

Suppose that on a circular route, the gas stations located along the route contain just enough gas for one full trip. Prove that if one starts at the right gas station with an empty tank, one can complete the route. The solution that is offered…
grayQuant
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Venn diagram puzzle problem

All batangos are crentons , some franters are volns, and some kijuxes are not batangos. If no kijuxes are franters, which of the following CANNOT be true, given each group was observed to have no more than 2 members. a) All volns are crentons, as…
stackdsewew
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Math Snake Puzzle

A colleague recently showed me the following puzzle game and I'm interested in how this can be solved. I thought it would be a good talking point for you guys as well :) A detailed description of the puzzle is here. A sequence of 7 cubes may be…
fml
  • 139
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How to tame a Rechenschlange

I found the following problem, called Rechenschlange (literal translation: calculation snake) in a German puzzle calendar: Fill the blanks with the numbers 1-9. Each number must only appear once. All operators are evaluated left to right. xx …
Heinzi
  • 131
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7 answers

Puzzle About Cubes (from the book thinking mathematically)

I want to confirm my solution to the given problem (solutions were not available in the book) I have eight cubes. Two of them are painted red, two white, two blue and two yellow, but otherwise they are indistinguishable. I wish to assemble them…
user119020
  • 283
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Behind which door is the princess?

Because of Alladin's forbidden love for the king's daughter, he has been sentenced to the usual punishment: death by tiger. As the king is a fair man, he has a fighting chance to escape his doom. He is kept in a room with four doors. Behind two…
Minhaz Pathan
  • 33
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Sets for which $a_k^2 = \frac{a_1+\ldots+a_n - a_k}{n-1}$

Let $n\geq2$ be an integer. Find all sets $\{a_1,\dots,a_n\}$ of real numbers with the property that for all $k \in \{1,\dots,n\}$: $$a_k^2 = \frac{a_1+\ldots+a_n - a_k}{n-1} .$$ In other words, for which the square of every element equals the mean…
Mike Daas
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Minimum number of squares required in grid so that the next square added is not isolated

Given a rectangular grid with $n$ rows and $m$ columns in which squares may be placed, what are minimum number of squares required so that the next square added cannot be placed in isolation? Isolation is defined as not attached to a side of at…
user247298
  • 133
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Number bag riddle — minimal solution?

The riddle: Consider $N$ different bags $B_1$ to $B_N$. Each bag may be filled with numbers. Can you fill these bags with numbers from $1$ to $N$ so that the following conditions hold? 1) $n \in B_n$ (The $n$-th bag contains $n$.) 2) $B_i \cap B_j…
chiru
  • 681
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How many squares are in this image? Is there a method to check?

In this image I have counted 14 but others say 18. Is there a method to check exactly?
EdwardD
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Does a solved sudoku game always have same sum? Is this sum unique to solved game?

Fundamentally, I'm looking for help on two things: Verification that my math is correct for the assumption that all Xs are Y. Proof that are the inverse is true, that all Y's are X, or, if it's not true, example of X that is outside the Y…
Anthony
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Three Proper Ladies on a train

Three proper ladies are traveling on a train. Each turns red within one second if they become aware of dirt on their face. They are too proper to tell the other if they have dirt, and there are no mirrors. The conductor tells them "At least one of…
Jim
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