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Difference between revisions of "2012 CEMC Gauss (Grade 8) Problems/Problem 4"

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==Problem==
 
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Points <math>P</math>, <math>Q</math>, and <math>R</math> lie in a straight line.
 
Points <math>P</math>, <math>Q</math>, and <math>R</math> lie in a straight line.
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~anabel.disher
 
~anabel.disher
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{{CEMC box|year=2012|competition=Gauss (Grade 8)|num-b=3|num-a=5}}

Latest revision as of 20:54, 18 October 2025

Problem

Points $P$, $Q$, and $R$ lie in a straight line.


An image is supposed to go here. You can help us out by creating one and editing it in. Thanks.


The value of $x$ is

$\text{ (A) }\  69\qquad\text{ (B) }\ 138\qquad\text{ (C) }\ 75\qquad\text{ (D) }\ 64\qquad\text{ (E) }\ 54$

Solution

Since $\overline{PQR}$ is a straight line, it forms an angle of $180^{\circ}$.

This means that we have the equation:

$42^{\circ} + x^{\circ} + x^{\circ} = 180^{\circ}$

$2x^{\circ} = 138^{\circ}$

$x^{\circ} = 69^{\circ}$

Thus, $x = \boxed{\textbf{(A) } 69}$

~anabel.disher

2012 CEMC Gauss (Grade 8) (ProblemsAnswer KeyResources)
Preceded by
Problem 3
Followed by
Problem 5
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
CEMC Gauss (Grade 8)