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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 />

726 Practice Test Eight Answers and Explanations<br />

6. B<br />

Difficulty: Low<br />

Strategic Advice: Make sure you read <strong>the</strong> question carefully<br />

here. In early problems, it's easy to leap to conclusions<br />

about what <strong>the</strong> question is asking; make sure you realize<br />

you're finding <strong>the</strong> length of a single side, not <strong>the</strong> entire<br />

perimeter of square A.<br />

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

Perimeter of A= 4(perimeter of 8) = 4(18) = 72<br />

One side of 8 = (perimeter of 8) 7 4 = 72 7 4 = 18<br />

7. c<br />

Difficulty: Medium<br />

Strategic Advice: You should always be sure that you know<br />

what you're solving <strong>for</strong> be<strong>for</strong>e you dive into a question; this<br />

can save you a lot of time in <strong>the</strong> end.<br />

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

CD and DE make up Cf. If Cf = 30 and CO is twice <strong>the</strong><br />

length of DE, <strong>the</strong>n CO = 20 and DE = 10. We are solving<br />

<strong>for</strong> CO, so <strong>the</strong> answer is (C).<br />

8. B<br />

Difficulty: Medium<br />

Strategic Advice: Whenever you see a question dealing<br />

with properties of odd or even numbers, you should always<br />

approach it <strong>the</strong> same way-by Picking Numbers. Remember<br />

that what is true <strong>for</strong> one odd or even number is generally<br />

true <strong>for</strong> all of <strong>the</strong>m. So pick <strong>the</strong> most simple odd or even<br />

numbers <strong>for</strong> your variables and just see what happens.<br />

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

Here you're told not only that a is an odd number but also<br />

that it's negative, so just pick a negative odd number <strong>for</strong> a. A<br />

good choice would be - 1 . Since b is positive as well as even,<br />

2 would be a good choice <strong>for</strong> b. Now all you have to do is<br />

plug those values into <strong>the</strong> answer choices. (Just don't <strong>for</strong>get<br />

<strong>the</strong> rules of multiplying and dividing by negative numbers.)<br />

(A) (- l) + 2 = l<br />

(B) -(- 1)(2) = 2<br />

(C) (- 1)(2) = -2<br />

(D) _1._ = -2<br />

-1<br />

(E) 2 - ( - l ) = 2 + l = 3<br />

The only one that is even and positive is (B).<br />

9. c<br />

Difficulty: Medium<br />

Strategic Advice: As with many word problems,<br />

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

question stem, is a good strategy to use here.<br />

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

Start with (C). If 5 pounds of pasta salad are needed, it<br />

would be enough to feed ei<strong>the</strong>r 30 adults or 50 children or<br />

some combination of <strong>the</strong> two. Since <strong>the</strong>re are 1 O children<br />

at <strong>the</strong> party, <strong>the</strong>y would need 1 pound of pasta salad, and<br />

<strong>the</strong> remaining 4 pounds <strong>for</strong> <strong>the</strong> adults. Since <strong>the</strong>re are 34 -<br />

l O = 24 adults at <strong>the</strong> party, and each pound of pasta salad<br />

feeds 6 adults, <strong>the</strong> remaining 4 pounds will feed 4 x 6 = 24<br />

adults, making (C) <strong>the</strong> correct choice.<br />

10. E<br />

Difficulty: Medium<br />

Strategic Advice: Careful application of <strong>the</strong> rules of<br />

exponents will yield results here and on Test Day.<br />

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

(-3a2b6)3 = (-3)3 (a2)3 (b6)3 = -27 02x3b6x3 = -27a6b i s<br />

11. B<br />

Difficulty: Medium<br />

Strategic Advice: Remember <strong>the</strong> major three-part <strong>for</strong>mula:<br />

average =<br />

sum of terms<br />

number of terms<br />

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

sum =27<br />

number of terms = 3<br />

So average = 1I = 9<br />

' 3

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