If A = {x ∈ N : x ≤ 25 and x is odd} and B = {x ∈ N : x ≤ 25 and 3 divides x}, what is |A ∩ B|?
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Answer and explanation
Correct answer: 4
A ∩ B contains natural numbers not exceeding 25 that are both odd and divisible by 3. The multiples of 3 up to 25 are 3, 6, 9, 12, 15, 18, 21, and 24. Among these, the odd multiples are 3, 9, 15, and 21. There are four such numbers, so |A ∩ B| = 4. Therefore, option A is correct.
Frequently asked questions
What is the correct answer to this question?
4
Why is this the correct answer?
A ∩ B contains natural numbers not exceeding 25 that are both odd and divisible by 3. The multiples of 3 up to 25 are 3, 6, 9, 12, 15, 18, 21, and 24. Among these, the odd multiples are 3, 9, 15, and 21. There are four such numbers, so |A ∩ B| = 4. Therefore, option A is correct.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Operations on Sets (Union, Intersection, Difference).
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