Ok (I haven't done this in a while), you're gonna want to divide 96 by 8. You get 12, multiply that by 10 and you get 120. Think of it sort of like fractions (if that helps at all).
the original price was $120 because $96 is 80% of the original price so you do 96 divided by 8. This equals 12. You then add twelve to 96 twice and you get $120. You can then check it by doing 120 x 0.8