Difference between revisions of "1985 AJHSME Problems/Problem 1"

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==Solution 1==
 
==Solution 1==
By the [[associative property]], we can rearrange the numbers in the numerator and the denominator:<math></math>\frac{3}{3}\cdot \frac{5}{5}\cdot\frac{7}{7}\cdot\frac{9}{9}\cdot\frac{11}{11}=1\cdot1\cdot1\cdot1\cdot1=\boxed{\text{(A)}\ 1}$.
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By the [[associative property]], we can rearrange the numbers in the numerator and the denominator. <cmath>\frac{3}{3}\cdot \frac{5}{5}\cdot\frac{7}{7}\cdot\frac{9}{9}\cdot\frac{11}{11}=1\cdot1\cdot1\cdot1\cdot1=\boxed{\text{(A)} 1}</cmath>
  
 
==Solution 2 (Brute force)==
 
==Solution 2 (Brute force)==

Revision as of 22:43, 12 March 2023

Problem

$\frac{3\times 5}{9\times 11}\times \frac{7\times 9\times 11}{3\times 5\times 7}=$

$\text{(A)}\ 1 \qquad \text{(B)}\ 0 \qquad \text{(C)}\ 49 \qquad \text{(D)}\ \frac{1}{49} \qquad \text{(E)}\ 50$

Solution 1

By the associative property, we can rearrange the numbers in the numerator and the denominator. \[\frac{3}{3}\cdot \frac{5}{5}\cdot\frac{7}{7}\cdot\frac{9}{9}\cdot\frac{11}{11}=1\cdot1\cdot1\cdot1\cdot1=\boxed{\text{(A)} 1}\]

Solution 2 (Brute force)

If you want to multiply it out, then it would be \[\frac{15}{99} \cdot \frac{693}{105}= \frac{10395}{10395}= \boxed{\text{(A)}\ 1}.\]

See Also

1985 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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