You purchased two video games originally costing $54 and $42. You received a 40% discount of $21.60 on the first game and a 15% discount of $6.30 on the second. To calculate the total percent discount on the combined purchase, the discounts of $21.60 + $6.30 = $27.90 are divided by the original total price of $54 + $42 = $96, resulting in a 28% discount on the total purchase.