Question

no of spanning trees with n nodes for a graph?

Answer 1

It depends on kind of Graph !

Disconnected Graph -> 0 spanning Tree

Complete Graph Kn -> n ^ n-2

Bipartite Graph, Km,n => m^n-1n^m-1

Does not fit in all cases -> Use https://en.wikipedia.org/wiki/Kirchhoff's_theorem this theorem

Answer 2

maximum spanning trees for vertices V is given by V^(V-2) .

3 vertices = 3^(3-2) =3

5 vertices = 5^(5-2)= 5³ = 125 and so on

Comments

For complete graph only

http://en.wikipedia.org/wiki/Spanning_tree

Answer 3

Apply Kirchoff's theorem:
http://en.wikipedia.org/wiki/Kirchhoff%27s_theorem