What is the set S₁ = {x : x ∈ ℕ, x is a divisor of 30, but x is not even}?
Answer and explanation
Correct answer: S₁ = {1, 3, 5, 15}
The positive natural-number divisors of 30 are 1, 2, 3, 5, 6, 10, 15, and 30. The condition says that the divisor must not be even, so we retain only the odd divisors. Among the listed divisors, 1, 3, 5, and 15 are odd, while 2, 6, 10, and 30 are even. Therefore, the roster form of the set is S₁ = {1, 3, 5, 15}, so option A is correct.
Frequently asked questions
What is the correct answer to this question?
S₁ = {1, 3, 5, 15}
Why is this the correct answer?
The positive natural-number divisors of 30 are 1, 2, 3, 5, 6, 10, 15, and 30. The condition says that the divisor must not be even, so we retain only the odd divisors. Among the listed divisors, 1, 3, 5, and 15 are odd, while 2, 6, 10, and 30 are even. Therefore, the roster form of the set is S₁ = {1, 3, 5, 15}, so option A is correct.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Sets and their representations.
