Difference between revisions of "1993 AJHSME Problems/Problem 1"

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(Solution 1)
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<math> \text{(A)}\ \{-4,-9\}\qquad\text{(B)}\ \{-3,-12\}\qquad\text{(C)}\ \left\{\frac{1}{2},-72\right\}\qquad\text{(D)}\ \{ 1,36\}\qquad\text{(E)}\ \left\{\frac{3}{2},24\right\} </math>
 
<math> \text{(A)}\ \{-4,-9\}\qquad\text{(B)}\ \{-3,-12\}\qquad\text{(C)}\ \left\{\frac{1}{2},-72\right\}\qquad\text{(D)}\ \{ 1,36\}\qquad\text{(E)}\ \left\{\frac{3}{2},24\right\} </math>
  
==Solution 1==
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Solution 1
A. The ordered pair <math>{-4,-9}</math> has a product of <math>-4\cdot-9=36</math>
 
  
B. The ordered pair <math>{-3,-12}</math> has a product of <math>-3\cdot-12=36</math>
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Let's calculate each of the answer choices and see which one DOES NOT equal 36.
  
C. The ordered pair <math>{1/12, -72}</math> has a product of <math>-36</math>
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A comes out to be -4 x -9= 36
  
D. The ordered pair <math>{1, 36}</math> has a product of <math>1\cdot36=36</math>
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B equals -3 x -12= 36
  
E. The ordered pair <math>{3/2, 24}</math> has a product of <math>3/2\cdot24=36</math>
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C is 1/2 x -72= -36
  
Since C is the only ordered pair which doesn't equal 36, <math>\boxed{\text{(C)}}</math> is the answer.
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D simplifies to 1 x 36= 36
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and E equals 3/2 x 24= 3 x 12= 36
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Thus, our answer is C. It is the only negative result.
  
 
==Solution 2==
 
==Solution 2==

Revision as of 18:28, 28 January 2022

Problem

Which pair of numbers does NOT have a product equal to $36$? $\text{(A)}\ \{-4,-9\}\qquad\text{(B)}\ \{-3,-12\}\qquad\text{(C)}\ \left\{\frac{1}{2},-72\right\}\qquad\text{(D)}\ \{ 1,36\}\qquad\text{(E)}\ \left\{\frac{3}{2},24\right\}$

Solution 1

Let's calculate each of the answer choices and see which one DOES NOT equal 36.

A comes out to be -4 x -9= 36

B equals -3 x -12= 36

C is 1/2 x -72= -36

D simplifies to 1 x 36= 36

and E equals 3/2 x 24= 3 x 12= 36

Thus, our answer is C. It is the only negative result.

Solution 2

We know that if we want a product of 36, both numbers have to be positive or negative. Scanning the number pairs, the only choice with one negative number and one positive number is $\boxed{\text{(C)}}$ ~fn106068

See Also

1993 AJHSME (ProblemsAnswer KeyResources)
Preceded by
First
Question
Followed by
Problem 2
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All AJHSME/AMC 8 Problems and Solutions

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