Question

Which of the set is singleton set?

(a) Set of odd prime numbers

(b) Set of even prime numbers

(c) Set of odd numbers

(d) Set of prime numbers

The question was posed to me in an internship interview.

The doubt is from Finite and Infinite Sets in portion Sets of Mathematics – Class 11

Answer 1

Correct option is (b) Set of even prime numbers

For explanation I would say: Set of even prime number {2} has one element so it is a singleton set.

Set of odd prime numbers {3,5,7,11,…………..}, set of odd numbers {1,3,5,7,……………}, set of prime numbers {2,3,5,…………} has infinite number of elements. So, they cannot form a singleton set.