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

12 Practice Tests for the SAT /
Practice Test Eight Answers and Explanations 735
7. B
Difficulty: Medium
Strategic Advice: Don't let the difference between inches
and feet confuse you here. Stay focused on using feet for
your answer.
Getting to the Answer:
For each hair bow, 3 pieces of 8-inch-long ribbon are used,
so that is 24 inches or 2 feet of ribbon. She made g hair
bows, so the total amount of ribbon she used was 2g.
So if the spool has 200 feet of ribbon, we can say that
she used 200 - 2g feet of ribbon.
8. B
Difficulty: High
Strategic Advice: If a geometry question does not provide a
diagram, sketch your own. Important things to notice about
this problem are the radius of the circle and the base and
height of the triangle.
Getting to the Answer:
To find the probability that a randomly selected point from
within the circle will fall within the triangle, find the area of
the triangle and divide it by the area of the circle.
Radius: 3
Base: 6
Height: 3
Area of triangle: -jC6)(3) = 9
Area of circle: n(32) = 97t
Probability: ..2_ = .l
7t
9. 1 2 or .5
97t
Difficulty: Medium
Strategic Advice: You're given that the whole line segment,
AE, is 3. Since D is the midpoint of AE, D must cutAf in
half. That means that AD is 1 -j and Of is 1 -j.
10. 70
Difficulty: Medium
Strategic Advice: If you notice that there is a triangle
on the right side of the figure with two labeled angles
from that triangle, you can probably solve this one.
Getting to the Answer:
The two labeled angles are 60° and 80°, so the third angle
of the triangle must be 1 80 - 60 - 80 = 40°. The 40°
angle and the two angles labeled cf' make up a straight line,
so 40 + d + d = 1 80. That means that 40 + 2d = 1 80,
2d = 140, and d = 70, so grid in the number 70.
17 11. 9, 1.88, or 1.89
Difficulty: Medium
Strategic Advice: Here you could do a lot of arithmetic
and get the right answer, but you should have noticed a
shortcut. Since this is a long string of numbers that are
being added and subtracted, you don't really need the
parentheses. Note: If there was a subtraction sign in front of
the parentheses, it would need to be distributed.
Getting to the Answer:
You can add or subtract these fractions in any order. Notice
that at one point you are adding t and at another point
subtracting t· Plus t minus t is just 0. The same is true
of 1
- and .l, so you can just cross out the terms - .l,
5 7 3
+ 1 - 1 1 1 d 1 h I
3, S ' + S' - 7 , an + 7' T at eaves you wit
x = 2 - .l = _.!._§_ - .l = .lZ. so grid in .lZ. (Not 1
9 9 9 9' 9 · 9 ·
You can't grid in mixed numbers.)
· h
Getting to the Answer:
AD is made up of three small line segments, all of which are
equal in length. That means that each one must measure
one-third of 1 -j. which is -j. So AB has length -j. and you
can put -j or .5 into your grid.