To solve this you will have to do a punnett square.
Since the yellow seed is dominate let that represent: A.
For the green seed color that is recessive let that represent: a.
The punnett square would look like this:
a a
A Aa Aa
a aa aa
This shows that there is a 50% chance for each.
50% for green seeds (recessive)
50% for yellow seeds (dominate)
Hope this helps! :3