GATE | GATE-CS-2017 (Set 2) | Question 27

G is undirected graph with n vertices and 25 edges such that each vertex has degree at least 3. Then the maximum possible value of n is ________
(A) 4
(B) 8
(C) 16
(D) 24

Answer: (C)
Explanation: As per handshaking lemma,

Sum of degree of all vertices < = 2 * no. of edges.

Let v be number of vertices in graph.
==> 3*v <= 2*25
==> Minimum value of v = 16

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