A marble paperweight shaped similar to a prism weighs 0.3 lb. How much does a similarly shaped marble paperweight weigh if its length, width, and height are doubled?
Don't get caught by saying the new weight will be double the old one. It isn't so.
Argument Let the first paper weight have a volume calculated from V = L * W * H W = weight = 3 pounds. density = W / V
The density is the same in both cases. It is made of marble.
New Volume V1 = 2L * 2W * 2 H V1 = 8 * L * W * H
W/V = W1 / V1 0. 3 / ( L * W * H) = x / (8 *L * W * H) Cross Multiply 0.3 * 8 * L * W * H = x * L * W * V 2. 4 * L * W * H = x * L * W * V Divide both sides by L * W * H 2.4 = W1
The new paper weight will be 2.4 pounds. 2.4 pounds <<<< answer.
