Question

why are odd numbers prime?

Answer 1

because they are having only one or two factors for it

Answer 2

All the prime nos prime execpt 2.

This is because all the even nos are divisible by 2 ie. 2 is the common factor of all the even nos.
So all the even no execpt 2 are composite nos.

Hence all the other prime nos are odd

hope that this would help