College roommates John and David were driving home to the same town for the holidays. John drove 55mph, and David, who left an hour later, drove 60mph. How long will it take for David to catch up to John?

Jorge wants to determine the enlarged dimensions of a digital photo to be used as wallpaper on his computer screen. the original photo was 800 pixels wide by 600 pixels high. the new photo will be 1,260 pixels wide. what will the new height be?