If A = {2, a + 1}, B = {2, 3}, and A = B, what is the value of a?
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Answer and explanation
Correct answer: 2
Two sets are equal only when they contain exactly the same elements; the order of elements does not matter. Set A already contains 2, so its other element, a + 1, must correspond to 3 in set B. Therefore, a + 1 = 3, and subtracting 1 from both sides gives a = 2. Hence option B is correct.
Frequently asked questions
What is the correct answer to this question?
2
Why is this the correct answer?
Two sets are equal only when they contain exactly the same elements; the order of elements does not matter. Set A already contains 2, so its other element, a + 1, must correspond to 3 in set B. Therefore, a + 1 = 3, and subtracting 1 from both sides gives a = 2. Hence option B is correct.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: The Empty Set, Finite and Infinite Sets, Equal Sets.
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