Can you give me some step-by-step instructions for this math problem: Katy, Wendi, and Carrie went to a bread-making party.  Katy brought three 5-pound bags of flour.  Wendi brought twice as much flour as Katy, but Carrie brought 5 pounds less than the amount of flour Wendi brought.  How much more flour, in ounces, did Carrie bring than Katy?