Given set $A=\{1,2,3,4\}$ and relation, $x R y$ if $x$ divides $y$.
$\Rightarrow $ Relation
$=\{(1,1),(2,2),(3,3),(4,4),(1,2),(1,3)(1,4),(2,4)\}$ Reflexive We have, $x R y \Leftrightarrow y / x$ for $x, y \in A$ For any $x \in A$, we have $x / x \Rightarrow x R x$
Thus, $x R x$ for all $x \in A .$ So, $R$ is reflexive on $A$. Symmetry $R$ ia not symmetry because, if $y / x$, then $x$ may not divide $y .$ For example $4 / 2$ but $2 / 4$ Transitive, Let $x, y, z \in A$, such that $x R y$ and $y R z .$
Then, $x R y$ and $y R z \Rightarrow \frac{y}{x}$ and $\frac{z}{y} \Rightarrow \frac{z}{x} .$
So, $R$ is a transitive relation on $A$.