Cosmo
11-07-2001, 09:02 PM
Can anyone tell me about the Rubiks cube. What I mean is, how many different combinations are possible? I came up with an answer that is like in the Quintillions, can this be right?
|
View Full Version : Math question, can you answer this? Cosmo 11-07-2001, 09:02 PM Can anyone tell me about the Rubiks cube. What I mean is, how many different combinations are possible? I came up with an answer that is like in the Quintillions, can this be right? ChaoticThoughts 11-07-2001, 10:50 PM I could be wrong, because Im not totally sure how to do the math, but I get the number- 60,466,176 i think its too low... u8nxprt 11-08-2001, 12:31 AM Yeah, it's some factorial problem. I can't think that hard right now. Thutmose 11-08-2001, 01:28 AM I havent fully thought out the problem (I am extremely busy this week), but here is a quick attempt... There are 26 small cubes of a rubiks cube. The 8 corners can be placed in any orientation, so there are 8! ways for them. There are 6 middle pieces, 6! ways for them. There are 12 "middle of edge pieces", each independent, so 12! ways for them. This leaves the total number of ways to be 6!12!8!, which is about 1.39 x 10^16 different ways to arrange the cube. However, there is more than one solution using this counting scheme... there are I believe 24 solutions using this scheme, not just 1. I might not have taken all the variables or contraints into consideration in this formulation of the problem, but it should suffice for now. Nate Scott 11-08-2001, 01:37 AM it's fun having a resident genius :) Momof6 11-08-2001, 09:39 AM Sorry.......I try not to do any math that makes my brain hurt!! Will have to buy videos to teach my kids algebra........ Brian 11-08-2001, 09:51 AM Originally posted by Momof6 Sorry.......I try not to do any math that makes my brain hurt!! Well, we have something else in common, anyway... Mechanical Engineer, imagine the headache at the end of the day... Cosmo 11-08-2001, 11:00 AM 43,252,003,274,489,856,000 92Notch 11-08-2001, 04:30 PM Originally posted by Cosmo 43,252,003,274,489,856,000 That’s about the amount of possibilities in 64bit encryption. ..actually somewhere between 65 and 66bit encryption. Cosmo 11-08-2001, 10:47 PM Uhh, is that good ? Icarus 11-09-2001, 09:11 AM Surely you have to divide by six. If you turn it over it's the same cube just upside down. There are six ways the cube can be turned around, therefore you have to divide by six. Wedge 11-09-2001, 09:25 AM I was playing around with this question yesterday and I found out it if you did one combination a second it takes 441 +/- million years to do all the combinations. 92Notch 11-09-2001, 12:38 PM Originally posted by Cosmo Uhh, is that good ? Depends on what side you are on, I guess :) Cosmo 11-09-2001, 09:29 PM I don't think you divide by six, all sides are a differnt color right? i thought for sure you guys would have all had the answerby now. Maybe I'm not as dumb as I look, or as dumb as the masked avenger says i am. Or maybe I am! u8nxprt 11-09-2001, 11:29 PM I found an article on the Rubik's cube. The professor didn't show the math, but here's his quote. "there are more than 43 quintillion (4.3252 x 10**19) different states that can be reached from any given configuration." http://www.engineer.ucla.edu/press/1997/korfcube.html I actually learned to solve that thing with a procedure in a guide book. hammegk 11-10-2001, 12:54 PM Here is better discussion: http://mathforum.org/dr.math/problems/glapa.4.11.01.html It confirms Cosmo's 4 x 10^19 post; I wish I understood it! :o Cosmo 11-10-2001, 04:07 PM Cosmo doesn't understand it either. I tried to solve it on a bet, but no one seems to know the right answer. By best Math subject was geometry, to give you an idea. Thutmose 11-10-2001, 06:41 PM I read that article and I understood it OK, but I couldnt explain it any better than that article does. For those of you who read my previous post and understood that, what that counting did not take into account were the multiple orientations of each small block in the cube. I only considered their positions. Thus, if you correct my answer for the multiple block rotations then you get the correct answer. The difficult part comes in counting the number of block positions. Cosmo 11-23-2001, 01:55 PM Thutmose, I am glad there are poeple like you to make up for peeeople like me. All part of gods plan I reckon. Wedge 11-23-2001, 02:02 PM Originally posted by Thutmose I read that article and I understood it OK, but I couldnt explain it any better than that article does. For those of you who read my previous post and understood that, what that counting did not take into account were the multiple orientations of each small block in the cube. I only considered their positions. Thus, if you correct my answer for the multiple block rotations then you get the correct answer. The difficult part comes in counting the number of block positions. I think you explained it much better, b/c they are taking into the fact that you could peel off the stickers and out them in any order.. while if you didn't the corner pieces would never change.. they would just simply rotate.. in other words take a rubix cube and see if you can make the three corner color change.. you can't they have to be beside each other.. just my train of thought.. :) Scott 11-25-2001, 05:18 AM so...according to a mathamatician (Spelling?) that i know... you can never be more than 52 moves away from solving a rubics cube.... cool huh?:D Wedge 11-28-2001, 04:18 PM Originally posted by Scott so...according to a mathamatician (Spelling?) that i know... you can never be more than 52 moves away from solving a rubics cube.... cool huh?:D well according to my mathmatician.. it's 20.. I guess my math guy likes to peel off the little stickers... LOL |