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

12 Practice Tests for the SAT
748 Practice Test Eight Answers and Explanations
Getting to the Answer:
The perimeters of the triangle and the square are equal, so
3t = 45. Since you want the ratio of the length of a side of
the square to the length of a side of the triangle, solve the
equation 3t = 45 for T. Dividing both sides of 3t = 45 by t
results in 3 = 5 . Dividing both sides by 4 gives you % =
f·
So
f = % and the ratio is 3:4.
9. B
Difficulty: High
Strategic Advice: For this question, you have to know not
only how to read graphs but also how to find a percent
decrease.
The population in 1986 is 500,000, since the bar above
1986 reaches to 5 on the graph and the graph is in units
of 100,000. The population in 1988 is 400,000. What's
the percent decrease in population if it goes from 500,000
to 400 000? It's just 5oo,ooo - 400,000 x 1000/o =
' 500,000
lOO,OOO x 1000/o =x 100% = 20% .
500,000
Getting to the Answer:
If the percent decrease in population from 1988 to 1990
is the same as the percent decrease from 1 986 to 1 988,
then from 1988 to 1990 the population also decreased
by 200/o. Then 200/o of the 1 988 population was 200/o of
400,000, or 80,000, so the 1 990 population was
400,000 - 80,000 = 320,000, (B).
10. E
Difficulty: Medium
Strategic Advice: Let's call Hillary's first installmentx dollars.
Then each of the second and third installments was also x
dollars, and each of her remaining nine installments wast
of x dollars, or}- dollars. Since her total payment was 600
dollars, and this total was made up of three payments of x
dollars each and nine payments of}- dollars each, you can
set up an equation and solve it for x.
Getting to the Answer:
3x + 9x = 600
2
6x +
9x = 600
2 2
15x = 600
2
x = _1_ (600) = 2( 40) = 80
15
Her first installment was 80 dollars.
11. D
Difficulty: Medium
Strategic Advice: You could try sketching each answer
choice on a number line to see which one produces the
given values. This could be somewhat time-consuming,
however, so you might instead want to think about the
absolute value of the difference between two numbers.
Getting to the Answer:
For example, I x - 2 I < 2 indicates that the difference
between x and 2 is less than 2 and therefore that x is
between 0 and 4. In this question, I x I ;::: 2 produces the
given pattern. The difference between x and 0 is greater than
or equal to 2, so the selected values on the number line are
less than or equal to -2 and greater than or equal to 2.
12. D
Difficulty: Medium
Strategic Advice: The line in the diagram is a vertical line,
so a line perpendicular to that line will be horizontal. If
you're not sure which of the answer choices represents
a horizontal line, you can sketch a few points to see what
each line looks like.
Getting to the Answer:
y = 3 is a horizontal line.