If A ⊆ B, then A ∪ B is equal to what?
Answer and explanation
Correct answer: B
The relation A ⊆ B means that every element of A is already an element of B. The union A ∪ B contains all elements that belong to A or B. Since A contributes no element outside B, taking the union adds nothing to B. Therefore, A ∪ B = B. Notice that A ∩ B = A, but the question asks for the union, so option B is correct.
Frequently asked questions
What is the correct answer to this question?
B
Why is this the correct answer?
The relation A ⊆ B means that every element of A is already an element of B. The union A ∪ B contains all elements that belong to A or B. Since A contributes no element outside B, taking the union adds nothing to B. Therefore, A ∪ B = B. Notice that A ∩ B = A, but the question asks for the union, so option B is correct.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Sets and their representations.
