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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$(T+H+I+N+K)^3 = THINK$ alfanumeric equation problem

There is an alfanumeric equation $$(T+H+I+N+K)^3 = THINK$$ What is $K$ that will be the right answer based on that equation? The answer will be one of 1, 2, 3, 4, or 5. but I don't know how to start it. Please help me. Thank you!
Dimas Riatmodjo
  • 115
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Is this generalized Sudoku solvable?

Sudoku is played on a 9x9 grid where you place the digits 1 through 9 in individual grid cells. The constraints are that every column must have all digits 1-9 and so must every row. On top of that, the 9x9 grid is broken up into a 3x3 grid of areas…
Alan Wolfe
  • 1,259
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Find a set of numbers that add to $25$ and can multiply to the highest product.

I left class today with a riddle. Find a set of numbers (does not specify what type) that add to 25, but must multiply to a number as high as possible. For example, $10+10+5 = 25, 10\times10\times5 = 500$. I started with $5+5+5+5+5 \ (5^5 = 3125)$…
Cillowing
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balance scale problem for 13 (not 12) items

The 12-item balance scale puzzle is very familiar. The object is to find the lone non-standard item (if one exists) out of a group of 12 seemingly identical items, using a balance scale and a maximum of three weighings. Did you know that it is…
tom
  • 29
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2 answers

12 boxes reference weight

I heard this puzzle from a friend, haven't heard back with the answer and it's driving me nuts! It seems like a variation of the counterfeit coin problem. You have twelve boxes, each containing 1 to 6 marbles. The marbles inside the boxes are…
C.K.
  • 21
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Numerical rebus

Given: ${AA}\times{BC}=BDDB$ Find $BDDB$: $1221$ $3663$ $4884$ $2112$ The way I solved it: First step - expansion & dividing by constant ($11$): $AA\times{BC}$=$11A\times{BC}$ $1221$ => $1221\div11$ => $111$ $3663$ => $3663\div11$ => $333$ $4884$…
artyh
  • 95
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Dividing a Rectangle into 3 Identical Triangles

I got this puzzle and would like to ask for your opinion. Is it possible to divide a rectangle into 3 identical triangles? If yes, how ? I couldn't do it. If no, why? Thanks. (this is a puzzle for fun!).
user3275222
  • 613
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Is the Cracker Barrel Peg Game/Peg Solitaire solvable in higher dimensions and is there proof?

Google didn't come up with a result: https://www.google.com/search?q=cracker+barrel+peg+game+solvability+in+higher+dimensions The Cracker Barrel Peg Game consists of a triangular board with 15 holes for pegs. 14 pegs go in to the holes with one…
Aly
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Generate all numbers from 1- 20 using 5,10,15,20 using operators *,/,+,-,^

I have to make all the numbers from 1-20 using the operators *,/,+,-,^ and the numbers 5,10,15,20. Specifically, how I make 14 and 16? Edit: Every number has to be used and only once. Parentheses are allowed. Operators can be used to any amount as…
Neo TheOne
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If 4+7+2 = 281435, 7+3+9 = 212781, 6+2+7 = 121456, and 2+8+5 = 164036, then what would 8+4+6 equal?

I wanna check my answer that it's Right or wrong? as there is no answer given for this question. According to me: 8+4+6= 32 24 72 <- is the correct Answer. This is the way how I found my answer: To get initial 4 digits of all mathematical…
Himanshu Verma
  • 21
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Books in the Library of Babel

I recently came upon a comment in the mathematics overflow stating that the infinite string of pi was similar to The Library of Babel. This library is a universe containing every possible combination of a 410 page book. There are a finite number…
Dave C
  • 123
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Making a 3*3 block in Bejeweled

More puzzle but still math: You surely know the rules of Bejeweled (or comparable games): Start in a stable state. Flip two adjacent cells. Everywhere where $>2$ equal symbols are adjacent horizontally or vertically, they vanish and everything on…
Hauke Reddmann
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How Old Are Children?

Two old friends, Jack and Bill, meet after a long time. Jack: Hey, how are you man? Bill: Not bad, got married and I have three kids now. Jack: That’s awesome. How old are they? Bill: The product of their ages is 72 and the sum of their ages is the…
Jaguar
  • 485
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Find relation between numbers

Is there a way to find the relation between numbers . I have 2 groups of numbers Group a 5 --> 20... 6 --> 32... 7 --> 112... 8 --> 192... 9 --> 576... 10 --> 1024... And group b 7 --> 56... 8 --> 80... 9 --> 432... 10 --> 672... Is there a…
user3767289
  • 25
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64 stones of different weight, find the heaviest one

There are 64 stones of different weights and a 2-sided scale. Explain how one can find two heaviest stones in 68 trials on this scale. Do you start by taking any two and then comparing it to all the others? It seems to take up too much trials.
Gerard L.
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