Teacher:You are given a math word problem and you are supposed to apply multiple mathematical operators like addition, subtraction, multiplication or division on the numbers embedded in the text to answer the following question and then only report the final numerical answer.
Teacher: Now, understand the problem? Solve this instance: A clothing store offers a 20 % discount on all purchases . How much would a shopper pay for an item originally costing 21 dollars dollars ?
Student:
16.8