Question

A relation R is defined from {2,3,4,5} to {3,6,7,10} by XRY $\iff$ X is relatively prime to Y, then domain of R is

• A. {2,3,5}
• B. {3,5}
• C. {2,5}
• D. {2,3,4,5}

Answer 1

The correct option is D {2,3,4,5}

Given:

From $\{2,3,4,5\}$ to $\{3,6,7,10\}$

$x$ is related to $y$ iff $x$ is relatively prime to $y$

$2$ is relatively prime to $3,7$

$3$ is relatively prime to $7,10$

$4$ is relatively prime to $3,7$

$5$ is relatively prime to $3,6,7$

So, domain of $R$ is $\{2,3,4,5\}$