Question

Given a plane graph, G having 2 connected component, having 6 vertices, 7 edges and 4 regions. What will be the number of connected components?

(a) 1

(b) 2

(c) 3

(d) 4

Origin of the question is Undirected Graph in chapter Graph of Data Structures & Algorithms I

I had been asked this question during an internship interview.

Answer 1

The correct option is (b) 2

Easiest explanation - Euler’s Identity says V – E + R  = 1+ number of connected components.