Neither-of-two percentage from two activities with overlap: In a town, 65% watch TV news, 40% read a newspaper, and 25% do both. What percentage do neither?
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A5%
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B10%
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C20%
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D15%
Answer
Correct Answer: 20%
Explanation
Introduction / Context:For two activities A and B, the union percentage is p(A) + p(B) − p(A ∩ B). The “neither” percentage is the complement of the union within 100%. This is a direct inclusion–exclusion application.
Given Data / Assumptions:
- p(TV) = 65%
- p(Newspaper) = 40%
- p(Both) = 25%
Concept / Approach:Compute union first, then subtract from 100% to get neither.
Step-by-Step Solution:Union = 65% + 40% − 25% = 80%Neither = 100% − 80% = 20%
Verification / Alternative check:Venn diagram logic: the four partitions sum to 100%; “neither” is whatever remains after accounting for the union.
Why Other Options Are Wrong:5%, 10%, 15% do not match the computed complement given the fixed union of 80%.
Common Pitfalls:Adding the given percentages without subtracting the overlap double-counts the intersection and yields 105% instead of 80%.
Final Answer:20%