If A ⊆ B ⊆ C, n(C) = 95, n(B) = 61, and n(A) = 28, what is n(C − B)?
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Answer and explanation
Correct answer: 34
The notation C − B means the elements that belong to C but do not belong to B. Since B is a subset of C, all 61 elements of B lie inside C. Therefore, the elements remaining in C outside B are n(C) − n(B) = 95 − 61 = 34. The value of n(A) is not needed because A lies inside B and does not affect C − B.
Frequently asked questions
What is the correct answer to this question?
34
Why is this the correct answer?
The notation C − B means the elements that belong to C but do not belong to B. Since B is a subset of C, all 61 elements of B lie inside C. Therefore, the elements remaining in C outside B are n(C) − n(B) = 95 − 61 = 34. The value of n(A) is not needed because A lies inside B and does not affect C − B.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Venn Diagrams.
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