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Algebra Difficulty 1.4 Junior Find the answer Canada

Natalie and Harpreet are the same height. Jiayin’s height is 161 cm. The average (mean) of the heights of Natalie, Harpreet and Jiayin is 171 cm. What is Natalie’s height?

$\text{161 cm}$
$\text{166 cm}$
$\text{176 cm}$
$\text{183 cm}$
$\text{191 cm}$

Your answer

A number or a short expression. Fractions can be typed as 3/2, and spacing doesn't matter.

Solution

Since the average of three heights is 171 cm, then the sum of these three heights is $\text{3 171 cm}$ or $\text{513 cm}$ .

Since Jiayin’s height is 161 cm, then the sum of Natalie’s and Harpreet’s heights must equal $\text{513 cm - 161 cm = 352 cm}$ .

Since Harpreet and Natalie are the same height, this height is $\text{352 cm 2 = 176 cm}$ .

Therefore, Natalie’s height is 176 cm.

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