If A = {x ∈ N : x ≤ 8 and x is not prime}, which set is A equal to?
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Answer and explanation
Correct answer: {1, 4, 6, 8}
The natural numbers not exceeding 8 are 1, 2, 3, 4, 5, 6, 7, and 8. Among these, the prime numbers are 2, 3, 5, and 7. Removing the primes leaves 1, 4, 6, and 8, so A = {1, 4, 6, 8}. Notice that 1 is neither prime nor composite, but it is certainly not prime, so it must be included.
Frequently asked questions
What is the correct answer to this question?
{1, 4, 6, 8}
Why is this the correct answer?
The natural numbers not exceeding 8 are 1, 2, 3, 4, 5, 6, 7, and 8. Among these, the prime numbers are 2, 3, 5, and 7. Removing the primes leaves 1, 4, 6, and 8, so A = {1, 4, 6, 8}. Notice that 1 is neither prime nor composite, but it is certainly not prime, so it must be included.
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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