If A and B are subsets of a universal set U, then (A \ B) ∪ (A ∩ B) is equal to which set?
Answer and explanation
Correct answer: A
Consider any element x of A. If x is not in B, then x belongs to A \ B. If x is in B, then x belongs to A ∩ B. These two cases cover every element of A, and both resulting sets contain only elements of A. Therefore their union is exactly A. This is the partition identity A = (A \ B) ∪ (A ∩ B).
Frequently asked questions
What is the correct answer to this question?
A
Why is this the correct answer?
Consider any element x of A. If x is not in B, then x belongs to A \ B. If x is in B, then x belongs to A ∩ B. These two cases cover every element of A, and both resulting sets contain only elements of A. Therefore their union is exactly A. This is the partition identity A = (A \ B) ∪ (A ∩ B).
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Operations on Sets (Union, Intersection, Difference).