If A ⊆ B, n(A) = 5, and n(B) = 5, which conclusion is correct?
Answer and explanation
Correct answer: A = B
When A is a subset of B, every element of A is contained in B. For finite sets, if A is a proper subset of B, then A must have fewer elements than B. Here both sets have cardinality 5, so A cannot be a proper subset of B. Since A ⊆ B and their cardinalities are equal, they must contain exactly the same elements; hence A = B. Option A is correct.
Frequently asked questions
What is the correct answer to this question?
A = B
Why is this the correct answer?
When A is a subset of B, every element of A is contained in B. For finite sets, if A is a proper subset of B, then A must have fewer elements than B. Here both sets have cardinality 5, so A cannot be a proper subset of B. Since A ⊆ B and their cardinalities are equal, they must contain exactly the same elements; hence A = B. Option A is correct.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Equal sets and Subsets.
