Difference between revisions of "1993 AJHSME Problems/Problem 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==
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==Solution 1==
 
A. The ordered pair <math>{-4,-9}</math> has a product of <math>-4\cdot-9=36</math>
 
A. The ordered pair <math>{-4,-9}</math> has a product of <math>-4\cdot-9=36</math>
  
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Since C is the only ordered pair which doesn't equal 36, <math>\boxed{\text{(C)}}</math> is the answer.
 
Since C is the only ordered pair which doesn't equal 36, <math>\boxed{\text{(C)}}</math> is the answer.
  
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==Solution 2==
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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 <math>\boxed{\text{(C)}}</math>
 
==See Also==
 
==See Also==
 
{{AJHSME box|year=1993|before=First<br />Question|num-a=2}}
 
{{AJHSME box|year=1993|before=First<br />Question|num-a=2}}
 
{{MAA Notice}}
 
{{MAA Notice}}

Revision as of 19:55, 23 July 2021

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

A. The ordered pair ${-4,-9}$ has a product of $-4\cdot-9=36$

B. The ordered pair ${-3,-12}$ has a product of $-3\cdot-12=36$

C. The ordered pair ${1/12, -72}$ has a product of $-36$

D. The ordered pair ${1, 36}$ has a product of $1\cdot36=36$

E. The ordered pair ${3/2, 24}$ has a product of $3/2\cdot24=36$

Since C is the only ordered pair which doesn't equal 36, $\boxed{\text{(C)}}$ is the answer.

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 $\boxed{\text{(C)}}$

See Also

1993 AJHSME (ProblemsAnswer KeyResources)
Preceded by
First
Question
Followed by
Problem 2
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
All AJHSME/AMC 8 Problems and Solutions

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