Which of the following is a singleton set?
Answer and explanation
Correct answer: {x ∈ Z : x² = 4 and x > 0}
A singleton set contains exactly one element. In option A, x² = 4 gives x = −2 or x = 2, but the additional condition x > 0 removes −2 and leaves only x = 2. Thus the set is {2}, which has one member. Option B contains two integers, −2 and 2; option C is empty if N begins at 1; and option D contains 0 and 1. Therefore, only option A is a singleton set.
Frequently asked questions
What is the correct answer to this question?
{x ∈ Z : x² = 4 and x > 0}
Why is this the correct answer?
A singleton set contains exactly one element. In option A, x² = 4 gives x = −2 or x = 2, but the additional condition x > 0 removes −2 and leaves only x = 2. Thus the set is {2}, which has one member. Option B contains two integers, −2 and 2; option C is empty if N begins at 1; and option D contains 0 and 1. Therefore, only option A is a singleton set.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: The Empty Set, Finite and Infinite Sets, Equal Sets.
