Let A = {x : x is a prime number and 14 < x < 16}. Which statement about A is correct?
Answer and explanation
Correct answer: A = ∅
The integers strictly between 14 and 16 contain only 15. However, 15 is not prime because it has divisors 1, 3, 5, and 15; in particular, it is divisible by 3 and 5. Thus no number satisfies both conditions in the set-builder description. Therefore A has no elements and A = ∅.
Frequently asked questions
What is the correct answer to this question?
A = ∅
Why is this the correct answer?
The integers strictly between 14 and 16 contain only 15. However, 15 is not prime because it has divisors 1, 3, 5, and 15; in particular, it is divisible by 3 and 5. Thus no number satisfies both conditions in the set-builder description. Therefore A has no elements and A = ∅.
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.