Today, everything in the store is on sale. The store offers a 20% discount.

A) The regular price of a t-shirt is $18. What is the discount price?

B) Which equation represents this problem?
a) y = 0.8x b) y = 0.2x c) y = 1.80x d) y = 1.20x

C) The discount price of a hat is $18. What is the regular price?