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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 />

Practice Test Three Answers and Explanations<br />

16. D<br />

Difficulty: Medium<br />

Strategic Advice: First, determine <strong>the</strong> equation <strong>for</strong> <strong>the</strong> daily<br />

cost. Then determine <strong>the</strong> cost of running <strong>the</strong> air conditioner<br />

<strong>for</strong> 90 days.<br />

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

daily cost = 0.12(8) + 0. 1 O(h - 8)<br />

cost <strong>for</strong> 90 days = 90[0. 12(8) + 0. 1 O(h - 8)]<br />

Choice (D) is correct.<br />

= 90(0. 12)8 + 9(h - 8)<br />

Note: Be sure to distribute <strong>the</strong> 90.<br />

17. E<br />

Difficulty: Medium<br />

Strategic Advice: The sum of <strong>the</strong> lengths of any two<br />

sides of a triangle is greater than <strong>the</strong> length of <strong>the</strong> third<br />

side. There<strong>for</strong>e, a + b > c, a + c > b, and c + b >a. Look<br />

through <strong>the</strong> answer choices to determine which is possible,<br />

keeping <strong>the</strong>se inequalities in mind.<br />

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

(A) c = b + a<br />

(B) c=b -a<br />

c+a=b<br />

(C) c= 2a + b<br />

If this was true, <strong>the</strong>n<br />

c > a + b<br />

(D) c + 2 = a+ b + 3<br />

c=a+b+ l<br />

Incorrect; c < a + b<br />

Incorrect; c + a > b<br />

Incorrect; c < a + b<br />

This could be not true because in this equation, c is greater<br />

than a + b.<br />

(E) c + 3 = a + b + 2<br />

c=a+ b-1<br />

This could be true because c is less than a + b.<br />

18. B<br />

Difficulty: High<br />

Strategic Advice: This question looks complicated, but if you<br />

notice that <strong>the</strong> common denominator of J.. + J.. is xy, <strong>the</strong>n<br />

l<br />

x y<br />

you can solve <strong>for</strong> -, which equals 6, and <strong>the</strong>n use algebra<br />

xy<br />

to answer <strong>the</strong> question.<br />

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

l + l = s<br />

x y<br />

L + =<br />

il'.±!2_<br />

xy xy xy<br />

Substitute ( ) = 6<br />

6(y +x) = 5<br />

6(y +x) = 1<br />

5<br />

=<br />

__!_<br />

5 6<br />

You could also Pick Numbers <strong>for</strong> x and y.<br />

19. c<br />

Difficulty: High<br />

Strategic Advice: If each team played 4 games with each<br />

of <strong>the</strong> o<strong>the</strong>r teams, <strong>the</strong>n each team played (7)( 4) = 28<br />

games. Use this number to determine how many total<br />

games were played.<br />

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

If 28 games were played by each team, and each game<br />

involved 2 teams, <strong>the</strong>n 28 ( ) = 28( 4) = 112. So 1 12<br />

games were played.<br />

20. E<br />

Difficulty: High<br />

Strategic Advice: If you know <strong>the</strong> length of two sides of a<br />

triangle, <strong>the</strong>n you also know something about <strong>the</strong> length of<br />

<strong>the</strong> third side; it's greater than <strong>the</strong> difference and less than <strong>the</strong><br />

sum of <strong>the</strong> two o<strong>the</strong>r sides. You have (x-2) <strong>for</strong> one side and<br />

(x + 2) <strong>for</strong> ano<strong>the</strong>r side, so use this knowledge to <strong>for</strong>m an<br />

inequality that represents <strong>the</strong> possible values of <strong>the</strong> third side.<br />

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

y < (x - 2) + (x + 2)<br />

y

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