Exercise · ZW-BINARY-RELATION-007 · ★★☆ Intermediate
Let \(A=\{1,2,3\}\) and \(R=\{(a,b)\in A\times A : a\le b\}\). Which of these pairs is in \(A\times A\) but not in \(R\)?
Choose one option.
Show answer
- C. \((2,1)\)
Explanation
\(R\) contains the pairs with \(a\le b\). For \((2,1)\) we have \(2>1\), so it is not in \(R\).
Review the concept: Binary relation
A set of ordered pairs \((a,b)\) specifying which elements of \(A\) are related to which elements of \(B\).
\[R \subseteq A \times B\]
More practice problems: binary relation
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