Difference between revisions of "1998 AJHSME Problems/Problem 1"

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===Solution 2===
 
===Solution 2===
  
Note that <math>\frac{6}{x+1}<\frac{6}{x}<\frac{6}{x-1}</math> (for <math>x>1</math>) and <math>\frac{x}{6}<\frac{x+1}{6}</math>. Therefore, we just need to compare <math>\frac{6}{x+1}</math> and <math>\frac{x}{6}</math>. Plugging in <math>x=7</math>, we get <math>\frac{3}{4}</math> and <math>\frac{7}{6}</math>, respectively, with <math>\frac{3}{4}<\frac{7}{6}</math>. Thus, the answer is <math>\boxed{(B) \frac{6}{x+1}}</math>.  
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Note that <math>\dfrac{6}{x+1}<\dfrac{6}{x}<\dfrac{6}{x-1}</math> (for <math>x>1</math>) and <math>\dfrac{x}{6}<\dfrac{x+1}{6}</math>. Therefore, we just need to compare <math>\dfrac{6}{x+1}</math> and <math>\dfrac{x}{6}</math>. Plugging in <math>x=7</math>, we get <math>\dfrac{3}{4}</math> and <math>\dfrac{7}{6}</math>, respectively, with <math>\dfrac{3}{4}<\dfrac{7}{6}</math>. Thus, the answer is <math>\boxed{(B) \dfrac{6}{x+1}}</math>.  
  
 
~By Leon0168
 
~By Leon0168

Latest revision as of 09:04, 11 October 2025

Problem

For $x=7$, which of the following is the smallest?

$\text{(A)}\ \dfrac{6}{x} \qquad \text{(B)}\ \dfrac{6}{x+1} \qquad \text{(C)}\ \dfrac{6}{x-1} \qquad \text{(D)}\ \dfrac{x}{6} \qquad \text{(E)}\ \dfrac{x+1}{6}$

Solutions

Solution 1

Plugging $x$ in for every answer choice would give

$\text{(A)}\ \dfrac{6}{7} \qquad \text{(B)}\ \dfrac{6}{8} \qquad \text{(C)}\ \dfrac{6}{6} \qquad \text{(D)}\ \dfrac{7}{6} \qquad \text{(E)}\ \dfrac{8}{6}$

From here, we can see that the smallest is answer choice $\boxed{B}$

Solution 2

Note that $\dfrac{6}{x+1}<\dfrac{6}{x}<\dfrac{6}{x-1}$ (for $x>1$) and $\dfrac{x}{6}<\dfrac{x+1}{6}$. Therefore, we just need to compare $\dfrac{6}{x+1}$ and $\dfrac{x}{6}$. Plugging in $x=7$, we get $\dfrac{3}{4}$ and $\dfrac{7}{6}$, respectively, with $\dfrac{3}{4}<\dfrac{7}{6}$. Thus, the answer is $\boxed{(B) \dfrac{6}{x+1}}$.

~By Leon0168

See also

1998 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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