GATE Overflow Test Series | Mixed Subjects | Test 3 | Question: 1

Question

The chromatic number of the following graph is ________

Answer 1

The chromatic number of a graph is the smallest number of colors needed to color the vertices so that no two adjacent vertices share the same color i.e., the smallest value of possible to obtain a $k$-coloring.

$\implies$The chromatic number of a planar graph is at most $4$.



So, the correct answer is $4$.