# K complete graph

1. Apr 29, 2008

### chaotixmonjuish

I'm having problems taking a stab at this question:

Find a formula for the number of edges in Kn. What happens to the ratio of edges to verticies as n increases?

Formula: n/2 * (n-1)
Ratio: this is the part I can't figure out. I assumed the ration is n/(n/2*(n-1))

Give a brief verbal argument that employs this rule of inference?

Find a necessary relationship between the number of edges and number of vertices's of a graph G if it can be represented on a Torus?

The last two parts have completely stumped me.

2. Apr 29, 2008

### daveyinaz

Doesn't the ratio of $x$ to $y$ mean $\frac{x}{y}$?