Answer:
15/100 * 20, because the meal is 20 dollars and to find the percent of something you divide it with 100 so you will divide 15 with 100 and you’ll get 0.15. Then you will times it with the amount the meal cost because thats the charge. So 0.15•20 and you’ll get $3. A 15% tip for a $20 meal is $3.