All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > General
Centrifugal Balance II (Posted on 2005-10-18) Difficulty: 5 of 5
A circular centrifuge has 30 slots spaced evenly around its circumference. Thirty samples need to be spun in the centrifuge, their masses being 1g, 2g, 3g, . . . 29g, 30g. How can all the samples be placed in the centrifuge at once while keeping it balanced properly?

For what other values of N is it possible to balance an N slot centrifuge with samples weighing 1g, 2g, 3g, . . . (N-1)g, Ng?

No Solution Yet Submitted by Brian Smith    
Rating: 4.2857 (7 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
Interesting problem | Comment 26 of 30 |

I don't think anyone has yet come up with the complete set of Ns that work.  It's such an interesting problem that I'd like to call perplexuser's attention to it again.

I noticed that some people were thinking about this in the wrong way.  Namely, "In order for the centrifuge to balance, each half must weigh equal to the other half, no matter how it is divided" is false.  For a counterexample, look no further than this following balanced centrifuge:

 1 0
0 1
1 0

That's all I have to say.


  Posted by Tristan on 2006-02-03 21:26:57
Please log in:
Login:
Password:
Remember me:
Sign up! | Forgot password


Search:
Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (3)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2017 by Animus Pactum Consulting. All rights reserved. Privacy Information