If A = {x : x is a prime number and x < 15} and B = {x : x is an odd number and x < 15}, what is A − B?
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Answer and explanation
Correct answer: {2}
The prime numbers less than 15 are A = {2, 3, 5, 7, 11, 13}. The odd numbers less than 15 are B = {1, 3, 5, 7, 9, 11, 13}. A − B contains elements in A that are not in B. Every prime in A except 2 is odd and therefore belongs to B. Removing those common elements leaves only 2, so option A is correct.
Frequently asked questions
What is the correct answer to this question?
{2}
Why is this the correct answer?
The prime numbers less than 15 are A = {2, 3, 5, 7, 11, 13}. The odd numbers less than 15 are B = {1, 3, 5, 7, 9, 11, 13}. A − B contains elements in A that are not in B. Every prime in A except 2 is odd and therefore belongs to B. Removing those common elements leaves only 2, so option A is correct.
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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