Which set is A = {x : x is a positive multiple of 5 less than 20}?
Answer and explanation
Correct answer: A = {5, 10, 15}
The positive multiples of 5 are 5, 10, 15, 20, and so on. The condition x < 20 excludes 20 and every larger multiple. Also, 0 is not positive, so it cannot be included. The remaining elements are exactly 5, 10, and 15. Therefore, A = {5, 10, 15}, which is option A. This is a finite set with three elements.
Frequently asked questions
What is the correct answer to this question?
A = {5, 10, 15}
Why is this the correct answer?
The positive multiples of 5 are 5, 10, 15, 20, and so on. The condition x < 20 excludes 20 and every larger multiple. Also, 0 is not positive, so it cannot be included. The remaining elements are exactly 5, 10, and 15. Therefore, A = {5, 10, 15}, which is option A. This is a finite set with three elements.
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.
