Emmanuel has opened an online t-shirt shop: Es Tees. He sells every t-shirt for $5; it costs him $2 to buy the t-shirt from a wholesaler. Emmanuel spends $15 to run Facebook ads for a week. His profit for that week was $12. What is his ROI and the correct mathematical formula?

Group of answer choices

80% / ($12/$15) x 100

800% / ($12/15) x 1000

8% / (12/$15) x 10

None of these are correct