In a Venn diagram, only A has 23, only B has 17, only C has 19, the three two-set-only regions have 8, 9, and 10, and the centre has 5. What is n(A ∪ B ∪ C)?
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Answer and explanation
Correct answer: 91
The union of three sets contains every region lying inside at least one of the three circles. These seven disjoint regions contain 23, 17, 19, 8, 9, 10, and 5 elements. Adding each region once gives 23 + 17 + 19 + 8 + 9 + 10 + 5 = 91. Therefore, option A is correct.
Frequently asked questions
What is the correct answer to this question?
91
Why is this the correct answer?
The union of three sets contains every region lying inside at least one of the three circles. These seven disjoint regions contain 23, 17, 19, 8, 9, 10, and 5 elements. Adding each region once gives 23 + 17 + 19 + 8 + 9 + 10 + 5 = 91. Therefore, option A is correct.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Venn Diagrams.
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