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12.Practice.Tests.for.the.SAT_2015-2016_1128p

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12 Practice <strong>Tests</strong> <strong>for</strong> <strong>the</strong> <strong>SAT</strong><br />

488<br />

Practice Test Five Answers and Explanations<br />

8. D<br />

Difficulty: Medium<br />

Strategic Advice: Adjacent angles are supplementary and<br />

equal 180°, and vertical angles are congruent, which means<br />

<strong>the</strong>y are equal to one ano<strong>the</strong>r.<br />

Getting to <strong>the</strong> Answer:<br />

Sa + 4a = 180<br />

9a = 180<br />

0 =20<br />

b=Sa<br />

5 x 20 = 100<br />

9. c<br />

Difficulty: Medium<br />

Strategic Advice: Factor to solve <strong>the</strong> first equation. Use<br />

those solutions to find <strong>the</strong> possible solutions to <strong>the</strong> second<br />

equation.<br />

Getting to <strong>the</strong> Answer:<br />

x2 +x= 20<br />

x2 +x-20=0<br />

(x + S)(x - 4)<br />

X=-5 X=4<br />

x2 -x<br />

X=-5<br />

(-5)2 - (-5) = 25 + 5 = 30<br />

or<br />

X=4<br />

(4)2 -4= 16-4= 12<br />

The answer is (C).<br />

10. B<br />

Difficulty: Medium<br />

Strategic Advice: The distance on <strong>the</strong> graph, except during<br />

<strong>the</strong> resting points, should always be increasing.<br />

Getting to <strong>the</strong> Answer:<br />

Find a graph that increases quickly until <strong>the</strong> 2 on <strong>the</strong><br />

y-axis, <strong>the</strong>n is a horizontal line <strong>for</strong> l 0 minutes on <strong>the</strong> x-axis,<br />

<strong>the</strong>n slowly increases until <strong>the</strong> 5-mile mark on <strong>the</strong> y-axis.<br />

The only graph that follows this pattern is (B).<br />

11. E<br />

Difficulty: Medium<br />

Strategic Advice: If 4 hats need to be <strong>the</strong> same color,<br />

decide how many of each o<strong>the</strong>r color of hats could be<br />

chosen be<strong>for</strong>e having 4 of any color.<br />

Getting to <strong>the</strong> Answer:<br />

After 12 selections, it is possible to have chosen boxes<br />

containing 3 hats of each color and still not have 4 of any<br />

color. So on <strong>the</strong> 13th selection, you will have chosen <strong>the</strong><br />

4th hat of one of <strong>the</strong> colors.<br />

12. c<br />

Difficulty: Medium<br />

Strategic Advice: To find <strong>the</strong> sum of <strong>the</strong> measures of <strong>the</strong><br />

interior angles of a polygon, use <strong>the</strong> equation (n - 2) x<br />

1 80, where n is <strong>the</strong> total number of angles in <strong>the</strong> polygon.<br />

A regular polygon means that all of <strong>the</strong> interior angles and<br />

sides are equal.<br />

Getting to <strong>the</strong> Answer:<br />

Sum of <strong>the</strong> interior angles: (8 - 2) x 180 = 1,080<br />

Measure of each interior angle: 1 ·80 = 135<br />

Angle C is 1 35°.<br />

Measure of all <strong>the</strong> interior angles of polygon BCOO:<br />

( 4 - 2) x 180 = 360<br />

You know that <strong>the</strong> angle <strong>for</strong>med by <strong>the</strong> line and angle B is<br />

equal to <strong>the</strong> angle <strong>for</strong>med by <strong>the</strong> line and angle D because<br />

<strong>the</strong> lengths of both lines are equal. This is because <strong>the</strong>y<br />

both run from <strong>the</strong> origin of <strong>the</strong> polygon to an angle on<br />

<strong>the</strong> polygon.<br />

360 - 135 - 90 = 135 = measure of angle B and 0.<br />

l 5 = 67.5 = measure of angle B.<br />

13. c<br />

Difficulty: Medium<br />

Strategic Advice: Use everything within <strong>the</strong> paren<strong>the</strong>ses to<br />

define x, not just <strong>the</strong> first term.<br />

Getting to <strong>the</strong> Answer:<br />

f(t - r) = 6(t - r)<br />

= 6t - 6r

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