Answer:
5 batches of orange paint.
Explanation:
Since we only have the amount of red paint Finley has, you have to divide 15 by 3, since we need 3 liters of red paint for 1 liter of orange paint. 15 divided by 3 equals 5, so Finley can only make 5 batches of orange paint when she has 15 liters of red paint.