two number cubes are rollede. what are the odds of getting s sum less than 7? is the answer 15 correct ?

ways to get less than seven;

1,1;1,2;1,3;1,4;1,5
2,1;2,2;2,3;2,4
3,1;3,2;3,3
4,1;4,2
5,1

So I count 15 ways to get less than seven, so there are 36-15 ways to get seven or more.

odds: 15:21