If \(A=\{\text{red},\text{blue},\text{green}\}\) and \(B=\{\text{blue},\text{yellow}\}\), what is \(A-B\)?
Answer and explanation
Correct answer: \(\{\text{red},\text{green}\}\)
By definition, \(A-B\) contains elements that are in A but not in B. The element blue belongs to both sets, so it must be removed from A. Red and green are in A and absent from B, giving \(A-B=\{\text{red},\text{green}\}\). Option B is the intersection, option C is not a subset of A, and option D is the union.
Frequently asked questions
What is the correct answer to this question?
\(\{\text{red},\text{green}\}\)
Why is this the correct answer?
By definition, \(A-B\) contains elements that are in A but not in B. The element blue belongs to both sets, so it must be removed from A. Red and green are in A and absent from B, giving \(A-B=\{\text{red},\text{green}\}\). Option B is the intersection, option C is not a subset of A, and option D is the union.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Operations on Sets (Union, Intersection, Difference).
