document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=313808>Question 313808</A>: <I><SPAN STYLE=\"word-break: break-all;\"> There are currently 74 million cars in a certain country, decreasing by 4.3% annually. How many years will it take for this country to have 46 million cars? (Round to the nearest year.) Use the exponential growth model P(t) = P0e^kt </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #224387 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=224387\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> There are currently 74 million cars in a certain country, decreasing by 4.3% annually. How many years will it take for this country to have 46 million cars? (Round to the nearest year.) <BR>\n" );
document.write( "Use the exponential growth model P(t) = Poe^(kt)<BR>\n" );
document.write( "----------------------<BR>\n" );
document.write( "Find \"k\":<BR>\n" );
document.write( "46 mil = 74 mil*e^(-0.043t)<BR>\n" );
document.write( "e^(-0.043t) = 0.6216<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Take the ln of both sides and solve for \"t\":<BR>\n" );
document.write( "-0.043t = -0.4754<BR>\n" );
document.write( "---<BR>\n" );
document.write( "t = 11.06 years<BR>\n" );
document.write( "======================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );