How are BOGO promotions calculated?

The discount for a “Buy One Get One” (BOGO) promotion is based on the lowest priced item. The discount is then applied to each item proportionately, reducing the value of each item. For example, If your first qualifying item is $60 and your second qualifying item is $40, the $60 item will be discounted by $24 and the $40 item will be discounted by $16, which gives a total discount of $40. If either item is returned, the return value will be equal to the original purchase price reduced by its prorated discount.