Which is the roster form of E₁ = {x ∈ ℕ : x is odd and x ≤ 11}?
Answer and explanation
Correct answer: {1, 3, 5, 7, 9, 11}
Assuming the standard school convention ℕ = {1, 2, 3, …}, the odd natural numbers not exceeding 11 are 1, 3, 5, 7, 9, and 11. The symbol ≤ means “less than or equal to,” so the endpoint 11 must be included. The set contains only odd numbers, so the even numbers are excluded. Therefore, the roster form is {1, 3, 5, 7, 9, 11}, which is option B.
Frequently asked questions
What is the correct answer to this question?
{1, 3, 5, 7, 9, 11}
Why is this the correct answer?
Assuming the standard school convention ℕ = {1, 2, 3, …}, the odd natural numbers not exceeding 11 are 1, 3, 5, 7, 9, and 11. The symbol ≤ means “less than or equal to,” so the endpoint 11 must be included. The set contains only odd numbers, so the even numbers are excluded. Therefore, the roster form is {1, 3, 5, 7, 9, 11}, which is option B.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Sets and their representations.
