Question

What is a star tree?

(a) A tree having a single internal vertex and n-1 leaves

(b) A tree having n vertices arranged in a line

(c) A tree which has 0 or more connected subtrees

(d) A tree which contains n vertices and n-1 cycles

The question was asked in an online interview.

This intriguing question comes from Properties of Tree topic in chapter Trees of Discrete Mathematics

Answer 1

The correct choice is (a) A tree having a single internal vertex and n-1 leaves

Explanation: A star tree of order n is a tree with as many leaves as possible or in other words a star tree is a tree that consists of a single internal vertex and n-1 leaves. However, an internal vertex is a vertex of degree at least 2.