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Problem 154

Geometry Difficulty 1.4 Multiple choice CEMC Pascal · Canada · 2023

A rectangular prism has a volume of 12 cm312\text{ cm}^3. A new prism is formed by
doubling the length, doubling the width, and tripling the height of the
original prism. The volume of this new prism is

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Official solution

Suppose that the original prism has length \ell cm, width ww cm, and height hh cm.

Since the volume of this prism is $12\$12\text{}
cm}^3,then, then \ell wh =
12$.

The new prism has length 22\ell cm,
width 2w2w cm, and height 3h3h cm.

The volume of this prism, in cm3\text{cm}^3, is $(2l)×\$(2l)\times (2w) ×\times (3h) = 2 ×2×3×\times 2 \times 3 \times lwh = 12 ×\times 12 = 144$.

Source: CEMC, University of Waterloo, licensed CC-BY-NC-4.0. Statement reproduced verbatim; metadata (topic, difficulty, ordering) added by this project.