36 people total, meeting in groups of 6. After 5 minutes, the groups shuffle into completely new groups. How many "rounds" can we go without people meeting with someone they've already met? [more inside]
posted by foggy out there now on Jul 31, 2010 - 27 answers

I've annoyed myself by getting stuck attempting to work out a silly maths problem relating to permutations. It's an extension of the 'how many odd socks do I have to pull out of a drawer before I find a pair' problem. Only my theoretical sock-wearer has three legs. And a penchant for odd socks. [more inside]
posted by Beautiful Screaming Lady on Sep 1, 2009 - 7 answers

I have a math question involving combinations and sets. [more inside]
posted by sonofslim on Apr 28, 2007 - 21 answers

Is there a standard ball picking algorithm? I have 10 balls that I want put in four boxes (A-D). Every box can hold zero to all balls. [more inside]
posted by davar on Feb 9, 2007 - 10 answers

Suppose there's a web form with 50 checkboxes (representing options or interests), and that checking one has no effect on any of the others. A user could select any two boxes, or a half dozen, or a different half dozen, or all 50. The only constraint on the form submission is that the user must check at least two boxes. How many possible combinations are there? [more inside]
posted by Tuwa on May 13, 2006 - 17 answers