Every natural number is factor to it self, so that R is reflexive
If (a,b) is an element of R, it means a is a factor of b, in this case b is not factor of a, so that (b,a) does not belongs to set R
so that the relation is not symmetric
Suppose that (a,b), (b,c) are elements of the relation R
it means a is factor of b and b is factor of c
it gives a is factor of c
Therefore, (a,c) is an element of R
It implies that the relation is transitive.
Hence, the relation is reflexive and transitive