If an article costs a store $17.45 and if it sells the article for $22.95, what percentage markup is it using?

1.) Sales Price - Original Cost / Sales Price * 100 = Percentage Markup
2.) Now substitute the values:
     Sales Price - Original Cost / Sales Price * 100 = Percentage Markup
                             $22.95 - $17.45 / $22.95 * 100 = Percentage Markup
                                                 $5.5 / 22.95 * 100 = Percentage Markup
.                                                          .2397 * 100 = 23.97%                        
3.) Therefore, the store uses 23.97% as Percentage Markup