You want to find the discount price. Set a relation to where the well i cant really explain it but do 20/100 = x/16.40 because 100% of the price is 16.40 dollars. You want to find 20% of that so you find what you multiply to 100 to get 16.40 which is 6.0975. Then you do the same thing for the 20% to find 20% of the price which is 3.28. sorry im trash at explaining but i hope i helped.
