Question 5
SetsThe universal set U consists of all integers. Subsets of U are defined as: A = {y : y ≤ 3}, B = {y : −5 < y < 12}, C = {y : −2 ≤ y < 5}. A∩ (B∪C)' is
- A.{y < −4}
- B.Ø
- C.{y < 0}
- D.{−4 ≤ y ≤ 3}
Show the answer and explanation
Answer: A ({y < −4})
Explanation
B∪C = {−5 < y < 12}, so (B∪C)' = {y ≤ −5 or y ≥ 12}. Intersecting with A (y ≤ 3) leaves y ≤ −5, which for integers is {y < −4}.