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

12 Practice Tests for the SAT
212
Practice Test Two Answers an d Exp l anations
Getting to t h e Answer:
Blue 5,700
Chairs with armrests
Green 6,500 - 5,700 = 800
Total 20,000 - 13,500 = 6,500
10. 180
Chairs without
armrests
13,500
Total
16,200
3,800
16,200 +
3,800 =
20,000
Difficu l ty: Low
Strategic A d vice: The first step to solving any math
question should be to ask yourself, "What am I trying to
solve for?" Asking this question here will get you a long way
toward solving this problem.
Getting to t h e Answer:
a = 30 percent of 400 = 400 x 0.3 = 120
b = 40 percent of a = 0.4 x 120 = 48
c = 25 percent of b = 0.25 x 48 = 12
a + b + c = 120 + 48 + 12 = 180
11. ]_
5
Difficu l ty: Low
Strategic A d vice: Whenever you are given two fractions
which are equal to each other, think of cross-multiplying.
Getting to t h e Answer:
lOq= 14
q = ..!1 =
10 1_
5
12. 3
Difficu l ty: Medium
Strategic A d vice: Figure out additional information based
on what is given and interpret the problem to understand
the "question behind the question:'
Getting to t h e Answer:
Line I is tangent to the circle, and line m intersects I at the
point of tangency. Therefore, I is perpendicular to m. If you
extend lines I and n so that they intersect, you can form a
30-60-90 triangle, where line n extended is the hypotenuse.
You are told that line n extended to the intersection with
line I measures 6. In other words, the hypotenuse is 6. The
measures of the sides of a 30-60-90 triangle are (x, x\/3,
2x). In this case, 6 = 2x, so x = 3 =the short side of the
triangle. In this case, the short side is OP. This is also the
radius of the circle, which is what the question asks for.
26
13. 5.2 or 5
Difficu l ty: Medium
Strategic A d vice: When the SAT puts a problem in words,
try to translate it into numbers. After that, simply solve
carefully.
Getting to t h e Answer:
2
·
5 o 2 is 2 = = 0.2. A t 1s va ue to 5. 5 + 0.2 =
S S
f l · 2 ( l ) l dd h. 1
26
5.2, or 5
.
14. 715
Difficu l ty: Medium
Strategic A d vice: With all math questions, especially percent
questions, be sure you are answering the correct question.
Getting to t h e Answer: Total up the percentage of
respondents who commute more than 0.5 hours and then
find the total respondents.
300/o + 200/o + 150/o = 650/o
15. 50
1,200 - l 00 = l , 100
l, 100 x 0.65 = 715
Difficu l ty: Medium
Strategic A d vice: Questions such as this one require you
to know certain facts or formulas. In this case, you need
to know that the sum of supplementary angles is 180°
and that the sum of the interior angles of a quadrilateral
is 360°.
Getting to t h e Answer:
First, find the angle supplementary to x (called x'), then
use it to find x. You can find x' because every quadrilateral
has 360 degrees; just sum up the other three angles and
subtract them from 360.
x' = 360 - (1 10 + 75 + 45)
x ' = 360 - 230
x' = 130
Since x is supplementary to x ' , we know that 180 - x' = x. So: