Jaylin is it making biscuits using the recipe how many cups of flour will he need to make 30 biscuits?

You want to find out how many cups of flour Jaylin needs to make 30 biscuits.
We currently know 2 cups of flour makes 20 biscuits.
We can halve the recipe down to make it simplier - simply divide all ingredients by 2 to halve it.
1 cup of flour = 10 biscuits
Since 1 cup of flour equals 10 biscuits, and 2 cups of flour equals 20 biscuits, we can safely say 3 cups of flour equals 30 biscuits.