Problema Solution
An open box is formed by cutting a 9 inch square measured from each corner and folding up the sides. If the volume of the carton is then 72 in3, what was the length of a side of the original square of cardboard?
Answer provided by our tutors
Let
x = the length of the side of the original square of cardboard, x>9
x - 2*9 = x - 18 the length of the sides of the box
h = 9 in the height of the box
V = 72 in^3 the volume of the box
V = h(x - 18)^2
V = 9(x - 8)^2
9(x - 8)^2 = 72
........
........
x = 10.83 in
The length of a side of the original square of cardboard is 10.83 inches.