# How to find the number of vertices and edges in these graphs?

How many vertices and edges are there in $K_{i,j}$ and $K_{i,j,k}$?

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Welcome to math.SE, mehtap karabacak: since you are a quite new user, I wanted to let you know a few things about the site. In order to get the best possible answers, it is helpful if you say in what context you encountered the problem, and what your thoughts on it are so far; this will prevent people from telling you things you already know, and help them write their answers at an appropriate level. – draks ... Jun 5 '12 at 22:39
Wikipedia is a useful resource – TMM Jun 5 '12 at 22:40

$K_{i,j}$ is defined as having a group of $i$ vertices and a group of $j$ vertices, with each vertex of the first group connected to each vertex of the second group, and no edges within a group. Is that your definition? If so, there are $i+j$ vertices (just count the two groups) and $ij$ edges as you pick one of the $i$ and one of the $j$ for each edge. How do you define Kijk (is it $K_{i,j,k}$)? If it is similar but with three groups of vertices, the same counting technique will work.
@mehtapkarabacak: if you don't know the definition, there is no way to answer the question. Do you understand the answer for $K_{i,j}$? The Wikipedia page that TMM cites gives a couple pictures that should help. – Ross Millikan Jun 5 '12 at 23:11