find the answer

Question

find width the dimensions of a shipping box given that the length is twice the width the height is 8 inches and the volume is 1600 inches

Answer 1

As a SAT question it should be done without pen (or pencil).

1600 / 8 = 200

2x² = 200

x² = 100

x = 10

Base is 20 by 10

Answer 2

The shipping box is a cube. The volume for a cube is:

V = L x W x H

V = 1600 in³

Length is twice the width. This equates to L = 2W

H = 8 in

Substitute L = 2W in the above equation, you get

1600 = 2W x W x 8

1600 = 16W²

W² = 1600 / 16 = 100

W = √100 = 10 in

To recheck your calculations,

L = 2W = 2 x 10 = 20 in

W = 10 in

H = 8 in

V = L x W x H = 20 x 10 x 8 = 1600 in³