If A = {x : x is odd and x is a positive divisor of 18}, which set equals A?
Answer and explanation
Correct answer: {1, 3, 9}
The positive divisors of 18 are 1, 2, 3, 6, 9, and 18. The condition requires the divisor to be odd, so we retain only 1, 3, and 9. Therefore A = {1, 3, 9}. Option B contains the even divisors, option C contains every positive divisor without applying the oddness condition, and option D incorrectly includes 6, which is even. This is a roster-form representation of a set defined by a property.
Frequently asked questions
What is the correct answer to this question?
{1, 3, 9}
Why is this the correct answer?
The positive divisors of 18 are 1, 2, 3, 6, 9, and 18. The condition requires the divisor to be odd, so we retain only 1, 3, and 9. Therefore A = {1, 3, 9}. Option B contains the even divisors, option C contains every positive divisor without applying the oddness condition, and option D incorrectly includes 6, which is even. This is a roster-form representation of a set defined by a property.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Sets and their representations.
