Graph Theory: A has 15 edges, Ā has 13 edges, how many vertices does A have?

Discrete Math: Graph Theory #54.

If A is a simple graph with 15 edges, and Ā has 13 edges, how many vertices does A have?

Can anyone give me the answer and how to arrive at it?

Thanks a bunch,

Yvonne(Sleepy)

Equation -> Handshaking Theorem?

Quote:

Originally Posted by

**kalagota** do you know this statement?

Let $\displaystyle \overline{G}$ be the complementary graph of $\displaystyle G$. Then

$\displaystyle |E(\overline{G})| + |E(G)| = \left({\begin{array}{c} |V(G)| \\ 2 \end{array}}\right)$

I don't believe I have seen this. Is this related or some rendition of the Handshaking Theorem?

-Ivy