Question

Graph G is obtained by adding vertex s to $K_{3,4}$ and making s adjacent to every vertex of $K_{3,4}.$ The minimum number of colours required to edge-colour G is

• A. 7

Answer 1

The correct option is A 7

7 edges are touching at S each of which needs to be colors by different color.
So 7 colors minimum are required. All other vertices have less than 7 edges touching.
So 7 colors only are required for edge coloring.