In this problem, you got a discount of 28% off the two video games. Here's how to figure this out.
First, you find out what the discount was on each video game. For the first one, you multiply 54 by .4. That gets you $21.6 -- so you got a discount of $21.60.
Then for the second one, you multiply 42 by .15 and you get 6.3.
So you add your discounts (they come to 27.90) and you divide that by the original total price (96.00) and you find that this is a 28% discount.