Difference between revisions of "1986 AHSME Problems/Problem 8"

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==Problem==
 
==Problem==
  
The population of the United States in <math>1980</math> was <math>226,504,825</math>. The area of the country is <math>3,615,122</math> square miles. The are <math>(5280)^{2}</math>  
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The population of the United States in <math>1980</math> was <math>226,504,825</math>. The area of the country is <math>3,615,122</math> square miles. There are <math>(5280)^{2}</math>  
 
square feet in one square mile. Which number below best approximates the average number of square feet per person?
 
square feet in one square mile. Which number below best approximates the average number of square feet per person?
  
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==Solution==
 
==Solution==
 
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With about <math>230</math> million people and under <math>4</math> million square miles, there are about <math>60</math> people per square mile. Since a square mile is about <math>(5000 \text{ft})^{2} = 25</math> million square feet, that gives approximately <math>\frac{25}{60}</math> of a million square feet per person. <math>\frac{25}{60}</math> is approximately half, so the answer is approximately half a million, which is <math>\boxed{E}</math>.
  
 
== See also ==
 
== See also ==

Revision as of 17:23, 1 April 2018

Problem

The population of the United States in $1980$ was $226,504,825$. The area of the country is $3,615,122$ square miles. There are $(5280)^{2}$ square feet in one square mile. Which number below best approximates the average number of square feet per person?

$\textbf{(A)}\ 5,000\qquad \textbf{(B)}\ 10,000\qquad \textbf{(C)}\ 50,000\qquad \textbf{(D)}\ 100,000\qquad \textbf{(E)}\ 500,000$


Solution

With about $230$ million people and under $4$ million square miles, there are about $60$ people per square mile. Since a square mile is about $(5000 \text{ft})^{2} = 25$ million square feet, that gives approximately $\frac{25}{60}$ of a million square feet per person. $\frac{25}{60}$ is approximately half, so the answer is approximately half a million, which is $\boxed{E}$.

See also

1986 AHSME (ProblemsAnswer KeyResources)
Preceded by
Problem 7
Followed by
Problem 9
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