If A = {p, q, r} and B = {q, r, s}, what is A ∪ (A ∩ B)?
Answer and explanation
Correct answer: {p, q, r}
The common elements of A and B are q and r, so A ∩ B = {q, r}. These elements are already contained in A = {p, q, r}. Taking the union of A with a subset of A adds nothing new. Therefore, A ∪ (A ∩ B) = A = {p, q, r}. This is the absorption identity A ∪ (A ∩ B) = A.
Frequently asked questions
What is the correct answer to this question?
{p, q, r}
Why is this the correct answer?
The common elements of A and B are q and r, so A ∩ B = {q, r}. These elements are already contained in A = {p, q, r}. Taking the union of A with a subset of A adds nothing new. Therefore, A ∪ (A ∩ B) = A = {p, q, r}. This is the absorption identity A ∪ (A ∩ B) = A.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Operations on Sets (Union, Intersection, Difference).