If A = {x ∈ N : x is a two-digit number}, what is the nature of A?
Answer and explanation
Correct answer: Finite set
The two-digit natural numbers are 10, 11, 12, and so on up to 99. Both the lower bound and upper bound are fixed, so only finitely many natural numbers satisfy the condition. In fact, the number of elements is 99 − 10 + 1 = 90. Therefore A is a finite set, not an empty set, an infinite set, or a singleton. Hence option B is correct.
Frequently asked questions
What is the correct answer to this question?
Finite set
Why is this the correct answer?
The two-digit natural numbers are 10, 11, 12, and so on up to 99. Both the lower bound and upper bound are fixed, so only finitely many natural numbers satisfy the condition. In fact, the number of elements is 99 − 10 + 1 = 90. Therefore A is a finite set, not an empty set, an infinite set, or a singleton. Hence option B is correct.
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.
