Mathematics Stack Exchange
Mathematics Stack Exchange

Questions tagged [recreational-mathematics]

Mathematics done just for fun, often disjoint from typical school mathematics curriculum. Also see the [puzzle] and [contest-math] tags.

Recreational mathematics is a general term for mathematical problems studied for the sake of pure intellectual curiosity, or just for the enjoyment of thinking about mathematics, without necessarily having any practical application or expectation of deep theoretical results.

Recreational mathematics problems are often easy to understand even for people without an extensive mathematical education, even if the theory they lead to may turn out to be surprisingly deep. Thus, recreational mathematics can serve to attract the curiosity of non-mathematicians and to inspire them to develop their mathematical skills further.

Many typical recreational mathematics problems fall into the fields of discrete mathematics (combinatorics, elementary number theory, etc.), probability theory and geometry. Important contributors to recreational mathematics are Sam Loyd and Martin Gardner.

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The motorcyclist's challenge

n walkers ${A}_{i}$ ($i=1,2,...,n$) start out from X to Y simultaneously with constant speeds ${a}_{1}<{a}_{2}<...<{a}_{n}$. At the same time, motorcyclist M with speed $m=1$ starts out from Y to carry them, as shown below: The motorcyclist can…
Eric
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Word problem (food for thought)

I thought of this question today as I was coming home from work in my car (probably because of my parents' anniversary). This problem assumes the parents of everyone in the world got married and everyone in the future gets married at some point in…
Jason
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Is it always possible to fit these pieces in a square?

Consider all possible pairs of squares that can fit in a row of length $n$ where every square has a width of 1. If I have a large square of width $n$, can all such pairs of squares fit in the large square simultaneously? It's hard to explain without…
Pazzaz
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"The Mario Party Problem"

My roommate and I were trying to figure this one out last night after a heated game of Mario Party: This is a minigame in Mario Party that pits 3 players on a team against 1 solo player. The game consists of 4 cannons, each with a corresponding…
FunkyDelPueblo
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How Many Clock Hand Positions Swap to a Valid Position?

My wording will not be exactly clear, but this is what I remember. Suppose you have a clock with minute and hour hands and you switch their places to form another correct time. How many such times can be formed in a clock?
rahul
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A funny number problem

Let each integer number from $1$ to $2n$ be ascribed to a vertex or a side of an $n$-gon (one number per vertex and per side). Let the weight of a side be the sum of three numbers "connected" to it (i.e. the number ascribed to the side and two…
user
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Count the number of fish caught in total if we are given the number of fishermen who caught at least $n$ fish.

Some fishermen caught some fish. No one caught more than 20 fish. $a_i$ is the number of fishermen who caught at least $i$ fish. How many fish were caught? So my guess is that the number of fish caught has to be $$ a_1+a_2+\ldots + a_{20}$$ I…
Castor Godinho
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The mystik spiral(challenge)

Still one of my favorite problems. Feel free to attempt to solve it. Start at a 0,0 Travel along the x axis in the positive direction a distance of 1 Turn 90 degrees counterclockwise go forward 1/2 of the distance of the previous step Repeat steps…
Aspwil
  • 105
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using numbers 1 to 9 only once to equal 1 million

Using digits 1,2,3,4,5,6,7,8,9 only once how do you equal 1 million. Adding, multiplication, subtraction and division
Mark
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How are Sudoku puzzles created?

I recently read about the connection between solving Sudoku puzzles (and other graph coloring problems) and Groebner bases. This doesn't lead to an efficient solution technique, but it does link a popular topic with some real mathematics, e.g., the…
KCd
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Can someone produce a sudoku puzzle where guessing more than one cell's value at a time is required?

Currently I have a sudoku puzzle solver program and I've tried all the puzzles I can find that are labeled the "hardest" on various sudoku video games and puzzle books. My solver has solved them all. It currently uses the following 4 polynomial time…
user2566092
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How to solve a puzzle with numerals

Any insights are welcome for this puzzle. The following equation is wrong: $103 - 102 = 3$. Move one numeral to make it correct. The numeral moved is: $0,1,2$ or $3$?
S.D.
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How to draw by hand mathematical figures?

Does there exist a kind of tutorial in order to learn to draw by hand complicated surfaces? For example, the two-sheeted covering of the Klein bottle (drawn by Jean-Pierre Petit in Le retournement non trivial du tore, Comptes Rendus Académie des…
Seirios
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How small is the smallest circle a car can drive?

Lets say we have a model of a car with two fixed back wheels and two wheels in front that steer in the same angle: The wheelbase $w$ is the fixed distance of the two wheel axes. $\alpha_m$ is the maximum angle we can steer What is the radius $r$…
Martin Thoma
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Can we identify the time if we know every angle between three hands of a watch?

Let $M, H, S$ be the minute hand, the hour hand, the second hand of a watch respectively. Also, let $A_{MH}, A_{MS}, A_{HS}$ be the angle between $M$ and $H$, $M$ and $S$, $H$ and $S$ respectively. Then, here is my question. Question : Can we…
mathlove
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