Answer:
20%
Explanation:
200 mocha flavored cupcakes of the 500 cupcakes were sold. (200/500).
Reduce to 2/5. Then multiply 20/20 to 2/5 and get 20/100.
20% cupcakes were mocha flavored.
The logic behind me rewriting the fraction to 20/100 was because 200/500 could easily be divided be 100 and 5.