Question

A directed graph or digraph can have directed cycle in which ______

(a) starting node and ending node are different

(b) starting node and ending node are same

(c) minimum four vertices can be there

(d) ending node does not exist

The question was posed to me by my college director while I was bunking the class.

Question is from Graphs topic in portion Graphs of Discrete Mathematics

Answer 1

The correct choice is (b) starting node and ending node are same

Easiest explanation: If the start node and end node are same in the path of a graph then it is termed as directed cycle i.e, c0 = cn. For instance, a c b a is a simple cycle in which start and end nodes are same(a). But, a c b b a is not a simple cycle as there is a loop <b,b>.