<span>Your answer seems perfectly logical in the world of math. Unfortunately, the world of retail sales calculates markup percentage differently. If a remember correctly, the markup percentage is based upon the final price. Try the following: X is the final selling price. So X minus 70% of X is equal to $66.00 : X-(0.7X)=66, 0.3X=66, 66/0.3=X, X=220