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Problem 141

Algebra Difficulty 1.1 Multiple choice CEMC Pascal · Canada · 2023

If $3 + \triangle = 5$ and
$\triangle + \square = 7$ , the value
of $\triangle + \triangle + \triangle + \square + \square$ is

Pick one

Official solution

Since $3 + \triangle = 5$ ,
then $\triangle = 5 - 3 = 2$ .

Since $\triangle + \square = 7$ and
$\triangle = 2$ , then $\square = 5$ .

Thus, $\triangle + \triangle + \triangle + \square + \square = 3 \times 2 + 2 \times 5 = 6 + 10 = 16$ .

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