If A = {10, 20, 30, 40} and B = {20, 40, 60}, how many elements are in A ∩ B?
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Answer and explanation
Correct answer: 2
The intersection A ∩ B contains only the elements that occur in both sets. Comparing the two sets, 20 appears in A and B, and 40 also appears in A and B. The elements 10 and 30 occur only in A, while 60 occurs only in B. Therefore, A ∩ B = {20, 40}, which has 2 elements. Hence option B is correct.
Frequently asked questions
What is the correct answer to this question?
2
Why is this the correct answer?
The intersection A ∩ B contains only the elements that occur in both sets. Comparing the two sets, 20 appears in A and B, and 40 also appears in A and B. The elements 10 and 30 occur only in A, while 60 occurs only in B. Therefore, A ∩ B = {20, 40}, which has 2 elements. Hence option B 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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