Question

What is a chromatic number?

(a) The maximum number of colors required for proper edge coloring of graph

(b) The maximum number of colors required for proper vertex coloring of graph

(c) The minimum number of colors required for proper vertex coloring of graph

(d) The minimum number of colors required for proper edge coloring of graph

This question was posed to me in final exam.

Question is taken from Graph Coloring in chapter Graph Coloring of Data Structures & Algorithms II

Answer 1

Correct answer is (c) The minimum number of colors required for proper vertex coloring of graph

Explanation: The minimum number of colors required for proper vertex coloring of graph is called chromatic number whereas the minimum number of colors required for proper edge coloring of graph is called chromatic index of a graph.