If \(U=\{x\in\mathbb{Z}:-3\le x\le 8\}\), \(A=\{x\in U:x+1\ge4\}\), and \(B=\{x\in U:x<6\}\), what is \(A'\cup B'\)?
Answer and explanation
Correct answer: \(\{-3,-2,-1,0,1,2,6,7,8\}\)
Within U, the condition \(x+1\ge4\) gives \(x\ge3\), so \(A=\{3,4,5,6,7,8\}\). Also, \(B=\{-3,-2,-1,0,1,2,3,4,5\}\). Therefore, \(A'\) contains \(-3,-2,-1,0,1,2\), while \(B'\) contains \(6,7,8\). Their union is \(\{-3,-2,-1,0,1,2,6,7,8\}\), option A.
Frequently asked questions
What is the correct answer to this question?
\(\{-3,-2,-1,0,1,2,6,7,8\}\)
Why is this the correct answer?
Within U, the condition \(x+1\ge4\) gives \(x\ge3\), so \(A=\{3,4,5,6,7,8\}\). Also, \(B=\{-3,-2,-1,0,1,2,3,4,5\}\). Therefore, \(A'\) contains \(-3,-2,-1,0,1,2\), while \(B'\) contains \(6,7,8\). Their union is \(\{-3,-2,-1,0,1,2,6,7,8\}\), option A.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Complement of a Set and Its Properties.