All Questions
8
questions
27
votes
1
answer
1k
views
Infinite Rubik's Cube
Is there an infinite analog to the Rubik's Cube? What does its solution-algorithm look like? For illustration, consider the Rubik's cube with infinite tiles to a side, on all sides, with sides of ...
- 649
2
votes
0
answers
276
views
When the 24 Game is solvable given the four cards?
Consider the 24 Game with a deck of cards that forms a set $ \Omega = \{1, 2, ..., 13\}$, and we try to compute 24 using addition, subtraction, division and multiplication in Rational numbers $\mathbb{...
- 268
19
votes
2
answers
3k
views
Obscuring squares of Rubik's cube
This is a combinatorial question related to Rubik's cube $3\times3\times3$ (and, in the end, its generalizations $n\times n\times n$). I assume that the readers are familiar with this puzzle. Let's ...
- 47.3k
3
votes
0
answers
407
views
When solving a big Rubik cube (100x100x100), do you reduce the solution to like 50x50x50, and then 25x25x25, and then like 10x10x10 and then 3x3x3?
My question is about Rubiks cube.
Say you're solving a 100x100x100 cube (you can see examples in youtube by computer program - https://www.youtube.com/watch?v=0cedyW6JdsQ)
When solving a big Rubik ...
- 3,942
23
votes
2
answers
3k
views
The Weaver Android app $\rightarrow$ cute combinatorics problem
There's an Android puzzle app called "The Weaver". My question is why every level seems to be solvable in far fewer moves than one might naively think.
Here's a link for people who want to play along ...
- 520
3
votes
0
answers
2k
views
Given a number of items, how many sets of three are there where no two sets are two thirds similar?
Sorry if the title isn't proper math-talk. Hopefully I can explain it better here.
So let's say we have a set. 1, 2, 3, 4, 5, 6, 7, 8, 9. I want to know how many groups of three can be made where no ...
29
votes
1
answer
5k
views
Six Frogs - Puzzle (order reversal using special transpositions)
I had come across a puzzle:
The six educated frogs in the illustration are trained to reverse their order, so that their numbers shall read 6, 5, 4, 3, 2, 1, with the blank square in its ...
- 683
2
votes
1
answer
333
views
When does an orthomorphism of the cyclic group exist?
I thought I would post (as a puzzle) one of my favourite results in combinatorics. I actually use variants of this result in research quite often. It's not impossible that someone will post an ...
- 21.1k