If n(B)=27 and n(A∩B)=11, how many elements are only in B?
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Answer and explanation
Correct answer: 16
The total set B is divided into the region only in B and the common region A∩B. Therefore n(B)=n(B−A)+n(A∩B). Substituting the given values gives n(B−A)=27−11=16. Thus option B is correct. The value 11 is the overlap, 27 is all of B, and 38 is greater than the total number of elements in B.
Frequently asked questions
What is the correct answer to this question?
16
Why is this the correct answer?
The total set B is divided into the region only in B and the common region A∩B. Therefore n(B)=n(B−A)+n(A∩B). Substituting the given values gives n(B−A)=27−11=16. Thus option B is correct. The value 11 is the overlap, 27 is all of B, and 38 is greater than the total number of elements in B.
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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