If A = {1, 2}, B = {2, 3}, and C = {3, 4}, what is (A ∪ B) ∩ C?
Advertisement
Answer and explanation
Correct answer: {3}
Evaluate the parenthesized union first. A ∪ B = {1, 2, 3}, since the repeated element 2 is written only once. Next, intersect this result with C = {3, 4}. The only element common to {1, 2, 3} and {3, 4} is 3. Thus, (A ∪ B) ∩ C = {3}. The answer is not {2}, because 2 is not an element of C.
Frequently asked questions
What is the correct answer to this question?
{3}
Why is this the correct answer?
Evaluate the parenthesized union first. A ∪ B = {1, 2, 3}, since the repeated element 2 is written only once. Next, intersect this result with C = {3, 4}. The only element common to {1, 2, 3} and {3, 4} is 3. Thus, (A ∪ B) ∩ C = {3}. The answer is not {2}, because 2 is not an element of C.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Operations on Sets (Union, Intersection, Difference).
Advertisement