The number of edges in a regular graph of degree d and n vertices is

2018

The number of edges in a regular graph of degree d and n vertices is

  1. A.

    maximum of n and d

  2. B.

    n + d

  3. C.

    nd

  4. D.

    nd / 2

Attempted by 120 students.

Show answer & explanation

Correct answer: D

In a regular graph with n vertices and degree d, the sum of all vertex degrees is nd. According to the Handshaking Lemma, this sum equals twice the number of edges (2E). Therefore, 2E = nd, which means the number of edges is E = nd/2.

A video solution is available for this question — log in and enroll to watch it.

Explore the full course: Isro