Answer:
She is correct because they need to find how much is the discounted price, which is 3. So to see what percentage it is, they need to see how much 3 is worth in comparison to 15. If we spilt 15 into 5 parts to make every part worth 20%, the answer would be 3. Thus Arianna is correct.
Step-by-step explanation:
1/5 (18-11) I believe this is what you mean?