Question: Rihanna has $50 to go to the supermarket. Rihanna bought 6 mangoes and 6 cartons of apple juice. Each mango cost $3 and each carton of apple juice cost $3. How much money does Rihanna have left? Think carefully first, then make a decision:
The cost of the mangoes is 6 mangoes × $3 / mango = $18. The cost of the apple juice is 6 cartons × $3 / carton = $18. Find the total cost of the groceries which is $18 + $18 = $36. Rihanna has $50 − $36 = $14 left. So the answer is 14.