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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 />

576 Practice Test Six Answers and Explanations<br />

2. B<br />

Difficulty: Medium<br />

Strategic Advice: The union of two sets consists of all <strong>the</strong><br />

elements that are in ei<strong>the</strong>r or both sets. The intersection<br />

of two sets consists of <strong>the</strong> elements that <strong>the</strong> sets have in<br />

common. Don't <strong>for</strong>get that you're looking <strong>for</strong> <strong>the</strong> difference<br />

between <strong>the</strong> number of elements in <strong>the</strong> union and <strong>the</strong><br />

intersection, not just <strong>the</strong> number of elements in <strong>the</strong> union<br />

or <strong>the</strong> intersection.<br />

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

The union of <strong>the</strong>se sets contains <strong>the</strong> letters A, E, I, 0, U, B,<br />

C, and D. This is 8 elements.<br />

The intersection contains <strong>the</strong> letters A and E. This is 2<br />

elements.<br />

8-2=6<br />

3. E<br />

Difficulty: Medium<br />

Strategic Advice: For Logic problems, be sure to know<br />

<strong>the</strong> difference between what may be true and what must<br />

be true.<br />

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

According to <strong>the</strong> list, fruits 1 and 4 must be apples.<br />

Fruit 7 may be an apple.<br />

4. E<br />

Difficulty: Medium<br />

Strategic Advice: Use <strong>the</strong> slope <strong>for</strong>mula to find <strong>the</strong> missing<br />

coordinate.<br />

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

Y 2<br />

- Y1<br />

m= --<br />

X 2<br />

- Xl<br />

_2, = z-(-1)<br />

12 -7 -5<br />

-<br />

-<br />

5 z+ 1<br />

--<br />

12 -12<br />

S=z+l<br />

4=z<br />

5. c<br />

Difficulty: Medium<br />

Strategic Advice: Althougn this looks like a complicated<br />

problem, all you really have to do is plug <strong>the</strong> given<br />

in<strong>for</strong>mation into <strong>the</strong> given equation and solve <strong>for</strong> x.<br />

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

The problem states that <strong>the</strong>re were 160 turtles in <strong>the</strong> pond<br />

9 years after it was discovered, so n = 160 and t = 9.<br />

9<br />

160 = (x)23 = (x)23 = 8x<br />

20 =x<br />

So <strong>the</strong>re were 20 turtles in <strong>the</strong> pond <strong>the</strong> year it was discovered.<br />

6. c<br />

Difficulty: Medium<br />

Strategic Advice: The graph of c(x) crosses <strong>the</strong> x-axis when<br />

c(x) equals 0. You can ei<strong>the</strong>r set c(x) equal to zero and see<br />

how many values of x are solutions or just sketch <strong>the</strong> graph<br />

and observe <strong>the</strong> number of times it crosses <strong>the</strong> x-axis.<br />

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

x2 - 6 = 0<br />

7. c<br />

x2 = 6<br />

x = ±\/6, so <strong>the</strong> graph crosses <strong>the</strong> x-axis twice.<br />

Difficulty: Medium<br />

Strategic Advice: See what in<strong>for</strong>mation you can glean from<br />

<strong>the</strong> graph. What should <strong>the</strong> slope of <strong>the</strong> line be like? Where<br />

would <strong>the</strong> y-intercept be?<br />

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

Because <strong>the</strong> position of <strong>the</strong> dots on <strong>the</strong> graph increases<br />

along <strong>the</strong> y-axis slightly faster than it increases along <strong>the</strong><br />

x-axis, <strong>the</strong> slope of <strong>the</strong> graph must be slightly greater than<br />

1. Although it is difficult to locate <strong>the</strong> y-intercept precisely,<br />

it must certainly be negative. Each of <strong>the</strong>se pieces of<br />

in<strong>for</strong>mation allows you to rule out some of <strong>the</strong> possible<br />

answers, leaving only one, y = 1 .3x - 3.<br />

8. A<br />

Difficulty: High<br />

Strategic Advice: What geometry fact can you use to get<br />

a, b, and c in <strong>the</strong> same equation? The fact that <strong>the</strong> interior

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