If \(A=\{p,q,r,s\}\) and \(B=\{r,s,t\}\), what is \(B-A\)?
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Answer and explanation
Correct answer: \(\{t\}\)
For \(B-A\), inspect the elements of B and keep only those that are not in A. B contains r, s, and t. Since r and s also occur in A, they are removed, leaving only t. Thus \(B-A=\{t\}\). The order matters: \(B-A\) is not the same operation as \(A-B\), and it is also not the union of the two sets.
Frequently asked questions
What is the correct answer to this question?
\(\{t\}\)
Why is this the correct answer?
For \(B-A\), inspect the elements of B and keep only those that are not in A. B contains r, s, and t. Since r and s also occur in A, they are removed, leaving only t. Thus \(B-A=\{t\}\). The order matters: \(B-A\) is not the same operation as \(A-B\), and it is also not the union of the two sets.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Operations on Sets (Union, Intersection, Difference).
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