A rain gutter is to be made of aluminum sheets that are 32 inches wide by turning up the edges 90. See the illustration. (a) What depth will provide maximum cross-sectional area and hence allow the most water to X flow? (b) What depths will allow at least 78 square inches of water to flow? X 32 -2x 32 . . . (a) The depth that will provide the maximum cross-sectional area is 8 inches. (b) The depths between in. and in. will allow at least 78 square inches of water to flow