Question 1187748
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If the number of cars is decreasing by 3.4% per year, then the number of cars remaining is getting multiplied by 100%-3.4% = 96.6% each year.  With a current count of 80 million, the number of millions of cars after n years will be<br>
{{{80(0.966^n)}}}<br>
We want to know when the number of cars will be 58 million:<br>
{{{80(0.966^n)=58}}}
{{{0.966^n=58/80}}}<br>
The quickest way to get an answer is by graphing on a graphing calculator.  However, since the topic you chose is logarithms, we should get the answer that way.<br>
{{{log((0.966^n))=log((58/80))}}}
{{{n*log((0.966))=log((58/80))}}}
{{{n=log((58/80))/log((0.966))}}}<br>
We still need to get the answer using a calculator; but we did use logarithms to solve the problem.<br>
I leave it to you to do the calculation and round the answer as directed.<br>