Search All of the Math Forum:
Views expressed in these public forums are not endorsed by
NCTM or The Math Forum.



Re: X/O Grid
Posted:
Dec 23, 2012 3:07 AM


In article <Pine.NEB.4.64.1212182213130.17186@panix3.panix.com>, William Elliot <marsh@panix.com> wrote:
> Consider an n by m grid of x's and o's. > > An xpath from the bottom squares of the grid to the top squares of the > grid considitues a seqence of horizontally or vertically adjacent > xsquares from some bottom xsquare to some top xsquare. Similar with > opaths. > > An exit is a top square that is connected to a bottom square by > either an xpath or an opath. For example, in the 8 by 3, x/o grid > > x x o o x x o o x > x o o x o x x x x > o o x x x o x o x > > has two oexits and three xexits for a total of five exits. > > In an n by m, x/o grid, what is the expected number of exits?
Look up percolation theory.
 Michael Press



