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part of the correct choice, and the correct answer is (C).
Special Strategies
There are certain special strategies that are useful only for the Mathematics Tests. These strategies, as you
will see, could not be applied to non–math tests. They take advantage of the multiple–choice format of the
tests to obtain answers by non–orthodox means.
Our first strategy is called “picking numbers.” This strategy can be used when the answer choices
are algebraic formulas. Let us return to a problem we just worked and solve it by “picking a number.”
EXAMPLE:
If k is a negative integer, then all of the following must be positive integers EXCEPT
(A) –k
(B)
(C) k
2
(D) (–k)
2
(E) –k
2
A very easy way to solve this problem is to pick a value for k, say k = –1. Now substitute –1 for k into the
answer choices:
(A)
– (–1) = 1 Positive
(B)  
(C)
(–1)
2
= 1 Positive
(D)
(– (–1))
2
= (1)
2
= 1 Positive
(E)
– (–1)
2
= – (1) = –1 Negative
A second strategy that is uniquely applicable to the Mathematics Tests is “working backwards.”
Here is an example:
EXAMPLE:
If 2
2x
= 64, then x =
(A)
(B) 1
(C)
(D) 2
(E) 3

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Lesson 8
196
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ARCO
■ SAT II Subject Tests
One of these five numbers is the value of x. Just substitute numbers for x until you find the right one:
(A) 2
2(1/2)
= 64
2 = 64 Wrong