2007 AMC 8 Problems/Problem 6

Problem

The average cost of a long-distance call in the USA in $1985$ was $41$ cents per minute, and the average cost of a long-distance call in the USA in $2005$ was $7$ cents per minute. Find the approximate percent decrease in the cost per minute of a long- distance call.

$\mathrm{(A)}\ 7 \qquad\mathrm{(B)}\ 17 \qquad\mathrm{(C)}\ 34 \qquad\mathrm{(D)}\ 41 \qquad\mathrm{(E)}\ 80$

Solution

The percent decrease is (the amount of decrease)/(original amount)

the amount of decrease is $41 - 7 = 34$

so the percent decrease is $\frac{34}{41}$ which is about $\boxed{\textbf{(E)}\ 80\%}$

Video Solution by SpreadTheMathLove

https://www.youtube.com/watch?v=omFpSGMWhFc

Video Solution by WhyMath

https://youtu.be/UtFO7ICGLgI

2007 AMC 8 (Problems • Answer Key • Resources)
Preceded by Problem 5	Followed by Problem 7
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All AJHSME/AMC 8 Problems and Solutions

The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions.

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2007 AMC 8 Problems/Problem 6

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Problem

Solution

Video Solution by SpreadTheMathLove

Video Solution by WhyMath

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