The relation “less than” in the set of natural numbers is

Since $x<y,y<z\Rightarrow x<z\forall x,y,z\in N$

$\therefore x R y, y R z\Rightarrow x R z$       $\therefore$relation is transitive

$\because$ x < y does not give y < x   $\therefore$relation is not symmetric

$\because$ x < x does not hold,            $\therefore$relation is not reflexive