WAEC 2014 Mathematics · Question 4
If x = {0, 2, 4, 6}, y = {1, 2, 3, 4} and z = {1, 3} are subsets of u = {x:0 x 6}, find x (Y' Z)
Options
- A.{0, 2, 6}
- B.{1, 3}
- C.{0, 6)
- D.{9}
Answer: C. {0, 6)
Explanation written with AI and checked against the answer key
Analyze the question: We need X ∩ (Y' ∪ Z), where the universal set U is described as {x : 0 ≥ x ≥ 6}. This is almost certainly a typing error for 0 ≤ x ≤ 6, so U = {0, 1, 2, 3, 4, 5, 6} (integers).
Concept:
- Y' (complement of Y) means the elements of U that are not in Y.
- ∪ combines the elements of both sets.
- ∩ picks only the elements common to both sets.
Solution:
- Y = {1, 2, 3, 4}, so Y' = U − Y = {0, 5, 6}.
- Y' ∪ Z = {0, 5, 6} ∪ {1, 3} = {0, 1, 3, 5, 6}.
- X ∩ (Y' ∪ Z) = {0, 2, 4, 6} ∩ {0, 1, 3, 5, 6} = {0, 6}.
Answer: {0, 6}, which is option C.
Note on the question: The universal set as written (0 ≥ x ≥ 6) is impossible, since no number is both at most 0 and at least 6. The intended meaning is 0 ≤ x ≤ 6, and that gives option C.
Tip: In set problems with complements, always write out the universal set first, then find the complement, then work through the brackets before the final intersection. Do it in the order: complement → union → intersection.
AI can make mistakes. Report anything that looks wrong.
Past questions © the examination body (JAMB/WAEC/NECO). DeeepSolve is not affiliated with them. Rights holders: see /copyright.
