If a simple, connected graph has 20 vertices, what is the maximum number of edges it can have?

Question

(Recall that a simple graph does not have loops and does not have multiple / parallel edges)

Answer 1

You can create an edge by connected any of the 2 vertices with an edge. There are 20 vertices. Therefore the total number of edges that can be made is ₂₀C₂ = 190