a$)$ Let G be a simple undirected graph. If it has n vertices, what is the maximum number of edges it could have? b$)$ Let G be a simple undirected graph with n $=4$ vertices and $6$ edges having weights $1,2,3,4,5,6.$ What is the maximum possible weight an MST of G can have? Hint: the MST will have n $1$ edges.