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

12 Practice Tests for the SAT
Practice Test Nine Answers and Explanations I
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instead of taken in the second paragraph.
SECTION 2
1. A
Difficulty: Low
Strategic Advice: We've got a lot of food, and we're making
some skimpy sandwiches with only 1 slice of ham and 1
slice of cheese in each one. If there are 75 slices of ham
and 75 slices of cheese, then we should be able to make
75 sandwiches, right? Certainly you can't make more than
75 sandwiches, so (D) and (E) can be eliminated. The
question is: Is there enough bread to make 75 sandwiches?
Getting to the Answer:
There are 1 20 slices of bread, and each sandwich gets
2 slices of bread, so there is enough bread for only 60
sandwiches. So the caterer can only make 60 sandwiches.
The correct answer is (A).
2. B
Difficulty: Low
Strategic Advice: This is a fairly straightforward algebra
question. To solve, simply plug the given values for x and y
into the equation.
Getting to the Answer:
You're given the expression x2 + 2xy + y2. Since x is 1 and y
is - 1, this expression becomes
x2 + 2xy + y2 = ( 1 )2 + 2 ( 1) (-1) + (- 1 )2
=1+(2)(-1)+1
=1+(-2) +1
=1- 2+1
=0
Be careful here with the operations involving negative
numbers. Remember that when you square - 1, or any
other negative number, you get a positive number, and
that adding a negative number is the same as subtracting
a positive number.
There's a shortcut here that you may have noticed. The
expression x2 + 2xy + y2 is equivalent to (x + y)2. Since
x + y = 1 + (- 1) = 1 - 1 = 0, (x + y)2 is also equal to 0.
3. c
Difficulty: Low
Strategic Advice: If you look at the drawing and think about
how gears work, you'll see that the teeth of each gear push
the gear next to it to make it go around. Let's call the gears A,
8, C, etc. from left to right.
Getting to the Answer:
If gear A is turned clockwise, then its teeth will push the teeth
on the left side of gear B down. This will make gear B turn
counterclockwise. Since gear B is turning counterclockwise,
the teeth will be moving up when they are on the right side,
touching gear C. That will push the teeth on the left side of
gear Cup and make gear C turn clockwise. Do you see the
pattern now? This will make 0 turn counterclockwise, E turn
clockwise, and finally F turn counterclockwise. Since A, C, and
E will turn clockwise and B, 0, and F will turn counterclockwise,
3 gears will turn counterclockwise, (C).
Questions 4-5
Whenever you have a graph question, it's a good idea to
spend at least a few seconds examining the graph before
you begin. Here you have what looks like part of a pie
chart and a bar graph, both describing the employees at
Company X. From the note under the title, you know that
there are 800 employees, and from the notes under the
graph, you know that 75 percent of them work full-time and
25 percent of them work part-time. Notice that the full-time
employees are represented by the bar graph, which gives
the number of full-time employees in each department,
whereas the part-time employees are represented by the
pie chart, which gives the numbers of part-time employees
as a percentage of the total number of employees.
4. D
Difficulty: Medium
Strategic Advice: In this percent word problem, you
already know from your examination of the graphs that 75
percent of the employees work full-time, 25 percent work
part-time, and there are 800 employees in all. That means
that there are 75% x 800 = 600 full-time employees and
25% x 800 = 200 part-time employees.
Getting to the Answer:
Since 600 is 400 more than 200, the number of full-timers
is 400 more than the number of part-timers, and the correct
answer is (D).