Batteries which normally sell for $1.89 a pack are on sale for $3.40 for To packs approximately what percentage markdown does this represent perfect per pack
percent decrease = (original number - new number) / original number ...*100 = (1.89 - 1.70) / 1.89....* 100 = 0.19 / 1.89...* 100 = 0.1 * 100 = 10 % <=== there is a 10% decrease per pack