Answer:
a) 80% b) $80 c) $ 320
Explanation:
Let the original price be $ 100
Discount= 20%
Hence, the selling price is= $ 100 ×

Hence, the selling price is= $ 80
let selling price x % of original price
$ 80=
× 100
x = 80%
Selling price is 80% of original price
b) If the original price= $ 400
Discount = $ 400 ×
80
Discount =$ 80
c) Selling price= $ 400

Selling price= 4× 80
Selling price= $320