Batteries which normally sell for $1.89 a pack are on sale for $3.40 for two packs. approximately what percentage markdown does this represent per pack?

Normally, two packs of batteries cost $1.89*2=$3.78.  The discounted price of $3.40 divided by the standard price of $3.78 for two packs is approximately .9, or 90 percent.  Therefore, we have an approximately ten percent discount with the sale.

markdown = (change in price / original price) * 100
markdown = [(1.89 - 1.70) / 1.89] * 100
                  = [0.19 / 1.89] * 100
                  = [0.101]  * 100
                  = 10.1  IS UR ANSWER OR 10