Which option correctly writes I={x: x is a positive factor of 9}?
Answer and explanation
Correct answer: I={1,3,9}
The governing concept is identifying positive divisors and writing them in roster form. The factor pairs of 9 are 1×9 and 3×3, so its positive factors are 1, 3, and 9. Six is not a factor because 9÷6 is not an integer, and zero cannot be a factor because division by zero is undefined. Therefore option A gives the complete set.
Frequently asked questions
What is the correct answer to this question?
I={1,3,9}
Why is this the correct answer?
The governing concept is identifying positive divisors and writing them in roster form. The factor pairs of 9 are 1×9 and 3×3, so its positive factors are 1, 3, and 9. Six is not a factor because 9÷6 is not an integer, and zero cannot be a factor because division by zero is undefined. Therefore option A gives the complete set.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Common Questions. Topic: General chapter practice.
