Questions tagged [matches]

A puzzle from 2-dimensional or 3-dimensional geometry centered around matchsticks.

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16
votes
6answers
2k views

180 degree rotation matchstick equality

Several matchstick digits are still digits when rotated by 180 degrees: Note that 2 is rotated to 2. Thus, we can make a matchstick arithmetic expression which is valid when rotated 180 degrees. For ...
8
votes
1answer
1k views

Matchsticks for lengths

You have been invited to an $n$-dimensional universe, where $n$ is an integer greater than $1$. Here, matchsticks are idealised lines of unit length, and they can pass through each other. They want ...
12
votes
11answers
12k views

Move only 2 matchsticks to find the equality

Just move two matchsticks to find the equality in the equation below: Note: There are two reasonable answers.
-6
votes
2answers
173 views

What is the shortest way to make an equality?

Ok, I realized that my puzzle was broken and my intended solution didn't work. I'll leave it there so that the not-so-hard earned answer doesn't go away. Rules: Round to the nearest hundredth The ...
-3
votes
5answers
466 views

How many matchsticks minimum can you move to make this true?

Ok here are some rules because it would be too easy/too hard without them Round to nearest 100th The first number cannot be an integer Needs to be an equality No mixed numbers Hint:
3
votes
11answers
1k views

Can you solve the following equation by moving exactly 3 matchsticks? [closed]

If yes, how? (every line is a matchstick)+--------- | | | +---------+ | | | | | | | | | ...
11
votes
11answers
9k views

Matchstick Puzzle from Jojo's Bizarre Adventure

Here's a puzzle from Jojo's Bizarre Adventure Part 6: Stone Ocean. Let me jojog your memory, it's from chapter 673. Any takers? Edit: Since there was an official answer found, I have marked that one ...
6
votes
3answers
1k views

How many matches can you fit? [closed]

I have a board with some matches on it, in the shape of a number. By adding one match, you make a larger number appear than before. By adding a second match, you make it smaller. By adding a third ...
4
votes
3answers
220 views

Two Fuses Burn for 45 Minutes [duplicate]

You have two pieces of delay fuse. One burns for 1 hour and the other burns for 30 minutes. Without a watch, clock, or timepiece at all... can you beyond any shadow of a doubt tell me when 45 minutes ...
7
votes
7answers
6k views

Make 4 congruent equilateral triangles with 6 matches in 2 dimensions [closed]

How would you make exactly four congruent equilateral triangles with just six matches of equal length in two dimensions? No other triangles may be created when you are done. Matches may not be bent, ...
7
votes
2answers
752 views

A matchstick game

On the table there is a $9\times9$ grid made of matchsticks, so that each of the $81$ little squares is bordered by exactly four matchsticks. Alice and Bob play the following game. Alice and Bob move ...
3
votes
1answer
1k views

Arrange matchsticks so that

Your challenge is to arrange matchsticks to make a pattern. Matchsticks are all the same length and cannot be broken. These are geometric arrangements: Make 4 triangles using 6 sticks. Make 3 X's ...
10
votes
4answers
3k views

Ummm what day was it, a matchstick puzzle

XXIII ------- = II VII All you need to do is move one matchstick from the roman numerals to make the equation true.
10
votes
1answer
529 views

Expected number of squares in a 20x10 grid with 1% chance of removing each edge

Suppose I make a 20x10 grid out of match sticks, using 21 columns of 10 match sticks and 11 rows of 20 match sticks: ...
14
votes
3answers
1k views

Touching Matchsticks

You are asked to place matchsticks on a flat surface such that each matchstick end meets three others, and no matches cross. It is easy to achieve this for patterns that extend indefintely: The ...
15
votes
1answer
1k views

Touching matchsticks with compass and straightedge

The question Touching Matchsticks asked for the smallest matchstick graph where every node is connected to four distinct edges. The Harborth Graph is the smallest such, with 104 edges connecting 52 ...
7
votes
1answer
697 views

Smallest number of matchsticks for a 3D structure with 6 matchsticks at each vertex

Make an as small as possible three dimensional structure of matchsticks, all of which have equal length, such that the end of each matchstick meets exactly five other ends. A matchstick is not allowed ...
3
votes
2answers
282 views

Find seven points so any three contain two of distance one

Choose 7 distinct points in the Euclidean plane so that among any 3 of those points, there are (at least) 2 that are a distance of exactly 1 apart.
7
votes
1answer
422 views

Ten matches on a table

Ten matches lay on a table and look like this: "XI+I=X". They create a correct equality. What is this equality? (Write it in arabic numeral system in your answer).

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