Chromatic number

Question

What is the chromatic number of K_n - e (complete graph with an edge removed)? 

Answer 1

look  if a graph is not complete then chromatic no is dmax.means higest degree of that graph.

u can check it for k4 and others.

so if we remove an edge from kn.then chromatic no is n-1.

Answer 2

(n-1)

Answer 3

n-1

where n is nodes.

in complete every1 is adjacent to each other. so we require n colours.

but removal of any edge causes one less adjacency.so N-1