GATE | GATE-IT-2004 | Question 5

What is the maximum number of edges in an acyclic undirected graph with n vertices?
(A) n-1
(B) n
(C) n + 1
(D) 2n-1

Answer: (A)
Explanation: n * (n – 1) / 2 when cyclic. But acyclic graph with the maximum number of edges is actually a spanning tree and therefore, correct answer is n-1 edges.
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