If A = {x : x is a prime number less than 20} and B = {2, 3, 5, 7, 11, 13, 17, 19}, then is A = B?
Answer and explanation
Correct answer: Yes, because both sets contain exactly the same prime numbers.
The prime natural numbers less than 20 are 2, 3, 5, 7, 11, 13, 17, and 19, which are exactly the elements listed in B. Therefore A and B contain the same elements, so A = B. The number 1 is neither prime nor composite, and 20 is not less than 20. Also, 2 is the smallest and the only even prime number.
Frequently asked questions
What is the correct answer to this question?
Yes, because both sets contain exactly the same prime numbers.
Why is this the correct answer?
The prime natural numbers less than 20 are 2, 3, 5, 7, 11, 13, 17, and 19, which are exactly the elements listed in B. Therefore A and B contain the same elements, so A = B. The number 1 is neither prime nor composite, and 20 is not less than 20. Also, 2 is the smallest and the only even prime number.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Equal sets and Subsets.
