If A = {x ∈ ℕ : x ≤ 20 and x is divisible by 5} and B = {5, 10, 15, 20}, which statement is correct?
Answer and explanation
Correct answer: A = B and n(A) = 4
The natural numbers not exceeding 20 that are divisible by 5 are 5, 10, 15, and 20. Thus A = {5, 10, 15, 20}, which is exactly the same set as B. Since there are four distinct elements, n(A) = 4. The condition x ≤ 20 includes 20, and no other positive multiple of 5 lies within the stated bound.
Frequently asked questions
What is the correct answer to this question?
A = B and n(A) = 4
Why is this the correct answer?
The natural numbers not exceeding 20 that are divisible by 5 are 5, 10, 15, and 20. Thus A = {5, 10, 15, 20}, which is exactly the same set as B. Since there are four distinct elements, n(A) = 4. The condition x ≤ 20 includes 20, and no other positive multiple of 5 lies within the stated bound.
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.
