The first thing we must do in this case is to calculate the surface area of the rectangular prism. We have then: A = 2 * ((L * h) + (L * w) + (h * w)) Where, L: long w: width h: height Substituting the values: A = 2 * ((7.5 * 10) + (7.5 * 2) + (10 * 2)) A = 220 Then, "Manufacturing each box requires 10% more cardboard than the box's surface area" Ar = 220 * 1.10 Ar = 242 242-220 = 22 Answer: is needed 22 in ^ 2 cardboard to make each box