Question

If $A=\{5,7,9,11\},B=\{9,10\}$ and $aRb$ means $a<b$ where $a\in A,b\in B,$ then which of the following is true?

• A. Range of $R=$ Co-domain of $R$
• B. Range of $R\ne$Co-domain of $R$
• C. Domain $=$ {5, 7}
• D. None of the above

Answer 1

The correct option is A Range of $R=$ Co-domain of $R$

Given that $R$ is a relation such that $aRb$ mean $a<b.$
$\Rightarrow R=\left\{\right(5,9),(5,10),(7,9),(7,10),(9,10\left)\right\}$

$\Rightarrow \text{Domain}=\{5,7,9\},$ the set of all first coordinates of the ordered pairs that belong to $R$

Also, co-domain $=\{9,10\},$ the second set in the relation $R$

Range $=\{9,10\},$ the set of second components of the ordered pairs which belong to $R$