Determine if valid or invalid by use of truth tables, standard forms, Euler diagrams or logical manipulation

" no odd number has a factor of 2. some prime numbers are odd. therefore some prime numbers have a factor of 2"

P-it is odd

q-it has a factor of 2

r-it is prime

p \to not q

r \to p

therefore r and q

or

p and not q

r and p

therefore r and q

i'm not sure which is right and i'm not sure how to prove it. please help!