The relation R defined in N as $\mathrm{aRb}\iff \mathrm{b}$ is divisible by a is

For any $\mathrm{a}\in \mathrm{N},$ we find that $\mathrm{a}|\mathrm{a}$ therefore R is reflexive but R is not transitive, because $\mathrm{aRb}$ does not imply that $\mathrm{bRa}$