In an exam, 36 students chose Hindi, 42 chose English, and 20 chose both subjects. How many students chose exactly one subject?
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Answer and explanation
Correct answer: 38
Students choosing only Hindi are \(36-20=16\), because the 20 students who chose both have to be removed. Students choosing only English are \(42-20=22\). Thus, the number choosing exactly one subject is \(16+22=38\). Equivalently, use \(n(A)+n(B)-2n(A\cap B)=36+42-40=38\). Therefore, option A is correct.
Frequently asked questions
What is the correct answer to this question?
38
Why is this the correct answer?
Students choosing only Hindi are \(36-20=16\), because the 20 students who chose both have to be removed. Students choosing only English are \(42-20=22\). Thus, the number choosing exactly one subject is \(16+22=38\). Equivalently, use \(n(A)+n(B)-2n(A\cap B)=36+42-40=38\). 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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