If A = {x : x ∈ ℕ, x is greater than 3 and less than 8}, what is the correct form of A?
Answer and explanation
Correct answer: {4, 5, 6, 7}
The governing concept is converting a set-builder description into roster form. We need natural numbers satisfying both strict inequalities 3 < x and x < 8. Checking the integers between the boundaries gives 4, 5, 6, and 7. Neither endpoint is included because both conditions are strict. Therefore A = {4, 5, 6, 7}, so option B is correct; the other options include 3 or 8 incorrectly.
Frequently asked questions
What is the correct answer to this question?
{4, 5, 6, 7}
Why is this the correct answer?
The governing concept is converting a set-builder description into roster form. We need natural numbers satisfying both strict inequalities 3 < x and x < 8. Checking the integers between the boundaries gives 4, 5, 6, and 7. Neither endpoint is included because both conditions are strict. Therefore A = {4, 5, 6, 7}, so option B is correct; the other options include 3 or 8 incorrectly.
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.
