If A = {x : x is a positive multiple of 2 or 3 less than 12}, what is A?
Answer and explanation
Correct answer: {2, 3, 4, 6, 8, 9, 10}
List the positive multiples of 2 less than 12: 2, 4, 6, 8, and 10. The positive multiples of 3 less than 12 are 3, 6, and 9. Because the condition uses “or,” take the union of these lists and write the repeated element 6 only once. Thus A = {2, 3, 4, 6, 8, 9, 10}; 12 is excluded because it is not less than 12.
Frequently asked questions
What is the correct answer to this question?
{2, 3, 4, 6, 8, 9, 10}
Why is this the correct answer?
List the positive multiples of 2 less than 12: 2, 4, 6, 8, and 10. The positive multiples of 3 less than 12 are 3, 6, and 9. Because the condition uses “or,” take the union of these lists and write the repeated element 6 only once. Thus A = {2, 3, 4, 6, 8, 9, 10}; 12 is excluded because it is not less than 12.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Operations on Sets (Union, Intersection, Difference).
