The answer for problem 15 I believe would be 36.75 feet of blue fabric because you find the total area, 3x4.5, which is 13.5, but that is for both the red and the blue fabric, so divide that by two, which gets you 6.75 inches. 1 inch=6 feet, so the answer would be 36.75 feet. This may not be correct. Hope this helped you to answer the other questions:)