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S.A.T. Math Testing Tactics. Tactic 5: Test the Answer Choices, Starting with “C”. On the S.A.T. Multiple Choice Questions there are 5 answer choices. The choices are listed in numerical order. “C” is the middle value. If “C” is too big, you can also eliminate the two bigger numbers.
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S.A.T. Math Testing Tactics Tactic 5: Test the Answer Choices, Starting with “C”
On the S.A.T. Multiple Choice Questions there are 5 answer choices. The choices are listed in numerical order. “C” is the middle value. If “C” is too big, you can also eliminate the two bigger numbers. If “C” is too small, you can also eliminate the two smaller numbers. WHY “C” ?
Solving directly is usually MUCH FASTER than testing your answer choices. • Only use Tactic #5 if you don’t see a straightforward solution strategy. BE CAREFUL!!!
Example 5.1 If the average (arithmetic mean) of 2, 7, and x is 12, what is the value of x? A) 9 B) 12 C) 21 D) 27 E) 36 Test “C” = 21 Test “D” = 27 (2+7+27)÷3 36÷3 12 (2+7+21)÷3 30÷3 10 Too small! Eliminate A + B also!
Example 5.2 If the sum of five consecutive even integers is 740, what is the largest of these integers? 142 144 146 152 156 Start with “C” = 146 If 146 is the LARGEST, what are the others? 146, 144, 142, 140, 138 146+144+142+140+138 = 710 Sum is too small! Eliminate A and B also! Try “D” = 152 If 152 is the LARGEST, what are the others? 152, 150, 148, 146, 144 152+150+148+146+144 = 740
Sometimes, testing “C” may not be easy to do. You can still be smart about the answers you choose to test. Of the answer choices shown, Which look “easy” to test? Example 5.3 If , then x = ? -1/8 0 5/8 1 9/8 Test “B” = 0 2 √(2∙0 +1) + 5 = 8 2√1 + 5 = 8 2 + 5 = 8 7 = 8 Too small! Eliminate A also. Test “D” = 1 2 √(2∙1 +1) + 5 = 8 2√3 + 5 = 8 3.46+ 5 = 8 8.46 = 8 Too big! Eliminate E also.
Example 5.4 What is the largest integer, n, such that is an integer? 1 2 3 4 5 Be Careful! This question asks for the LARGEST value that works. This implies that there may be more than one answer that makes the expression an integer. Instead of starting in the middle, we should start testing the LARGEST number. Test “E” = 5 112/25 112/32 3.5 Not an integer Test “D” = 4 112/24 112/16 7 Integer! Note: 1 gives you an integer 2 gives you an integer 3 gives you an integer
If you need to “Back-solve” by testing the answer choices– be smart about it. Try not to simply think “Well, that didn’t work.” Think about your test. Answers that are too big or too small may help you eliminate other choices. “C” is the middle– a good starting guess. If the problem refers to a largest or smallest answer, try plugging in the largest or smallest choice! In Conclusion…