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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> j<br />

Practice Test One Answers and Explanations<br />

111<br />

13. D<br />

Difficulty: Medium<br />

Strategic Advice: Don't be intimidated by radicals in <strong>the</strong><br />

denominator. Cross-multiply to remove <strong>the</strong> radical from<br />

<strong>the</strong> denominator and <strong>the</strong>n square both sides. This converts<br />

<strong>the</strong> problem into a familiar <strong>for</strong>m, a quadratic equation.<br />

Backsolving, or plugging <strong>the</strong> answers into <strong>the</strong> question<br />

stem, would also work well.<br />

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

14x<br />

=7<br />

V2x + 2<br />

14x= 7Y2x + 2<br />

2x = V2x + 2<br />

4x2 = 2x + 2<br />

4x2 - 2x-2 = O<br />

Simplify <strong>the</strong> equation fur<strong>the</strong>r by dividing both sides by 2,<br />

<strong>the</strong>n factor <strong>the</strong> equation to solve <strong>for</strong> x.<br />

2x2 -x- 1=0<br />

(2x + l)(x - 1) =0<br />

14. D<br />

Difficulty: Medium<br />

2x + 1 = 0 or x - 1 = 0<br />

x = -- 1 - or x = 1<br />

2<br />

Strategic Advice: Remember that <strong>the</strong>re are always two<br />

possibilities when solving absolute value equations. If you<br />

get stuck, try Backsolving, or plugging <strong>the</strong> answers into <strong>the</strong><br />

question stem.<br />

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

2r -2=8<br />

2r = 10<br />

r=5<br />

3r + 2 = 17 or -(3r + 2) = 17<br />

3r = 1 5 or 3r = -19<br />

-19<br />

r=5 or r=-- 3<br />

The only value that solves both equations is r = 5.<br />

15. E<br />

Difficulty: Medium<br />

Strategic Advice: This problem is designed to let you try out<br />

this procedure. Don't worry about having major insightsjust<br />

plug in <strong>the</strong> given number and see what happens. This<br />

will help you gain <strong>the</strong> insight you need <strong>for</strong> <strong>the</strong> next two<br />

questions.<br />

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

Choose 6. 127.<br />

6.127 x 100=612.7<br />

The smallest integer greater than or equal to 612.7 is 613<br />

Gust round up).<br />

613 + 12 = 625<br />

Print 625.<br />

16. D<br />

Difficulty: Medium<br />

Strategic Advice: You can attack this by ei<strong>the</strong>r trying to work<br />

backward with each of <strong>the</strong> answers or thinking about what<br />

kinds of results you can get from <strong>the</strong> procedure.<br />

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

Choose a number between 0 and 9.9.<br />

The result is between 0 and 990.<br />

Round up to nearest integer-now <strong>the</strong> number is an integer<br />

between O and 990.<br />

Add 12-now <strong>the</strong> number is an integer between 12<br />

and 1,002.<br />

Print <strong>the</strong> number from step 4.<br />

(A) Doesn't work because it's too small<br />

(B) Doesn't work because it's too small<br />

(C) Not an integer<br />

(D) Correct<br />

(E) Too large<br />

17. c<br />

Difficulty: Medium<br />

Strategic Advice: Try plugging a number into <strong>the</strong> reordered<br />

steps to see if you still get <strong>the</strong> same answer.<br />

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

We can try 6.1 27 again (<strong>the</strong> number doesn't change in 5,<br />

so we'll only show 1-4).

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