If A is the set of natural numbers whose square is 25, then A is equal to which set?
Answer and explanation
Correct answer: {5}
We need natural numbers n such that n² = 25. Over the integers, the equation has two solutions, n = 5 and n = −5. However, the question restricts n to natural numbers, and −5 is not natural. Since 5² = 25, the only allowed element is 5. Therefore, A = {5}, a singleton set.
Frequently asked questions
What is the correct answer to this question?
{5}
Why is this the correct answer?
We need natural numbers n such that n² = 25. Over the integers, the equation has two solutions, n = 5 and n = −5. However, the question restricts n to natural numbers, and −5 is not natural. Since 5² = 25, the only allowed element is 5. Therefore, A = {5}, 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.