Question

Cereal is packaged in a box shaped like a rectangular prism with a base 7.5 inches by 2 inches and a height of 10 inches. Manufacturing each box requires 10% more cardboard than the box's surface area. How much cardboard is needed to make each box?

Answer 1

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