Two game titles numbered 1 through nine are selected at random from a box without replacement. If their sum is even what is the probability that both numbers are odd

Well I know that even numbers are 2,4,6,8

So my sums would be 2+2,3+1,4+2,3+3,6+2,5+1,7+1,4+4,7+1,4+4,1+1,5+3

So I have 10 sums and 6 are with odd numbers.

So I thought of doing 6/18 / 10/18 but apparently this is wrong.