document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1020461>Question 1020461</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Good morning. Please help me solve this question.<BR>\n" );
document.write( "Approximately .25 of all glass bottles distributed will be recycled each year. A beverage company distributes 390000 bottles. The number still in use after t years is N(t)=390000(.5)^t. After how many years will 60000 bottles still be in use?\r<BR>\n" );
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document.write( "I think I'll need to solve for t and replace N(t) with 60000. I can not figure out how to solve for t when its the exponent. Please help. Thank you! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #636341 by </B><A HREF=/tutors/aboutme.mpl?userid=Cromlix><B>Cromlix(4381)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Cromlix><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/cgi-bin/show-face.mpl?user=Cromlix><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=636341\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Hi there,<BR>\n" );
document.write( "N(t) =390000(.5)^t<BR>\n" );
document.write( "60000 = 390000(.5)^t<BR>\n" );
document.write( "60000/390000 = (.5)^t<BR>\n" );
document.write( "0.153846 = (.5)^t<BR>\n" );
document.write( "log 0.153846 log(.5)^t<BR>\n" );
document.write( "log 0.153846 = t log(.5)<BR>\n" );
document.write( "t = log 0153846/log (.5)<BR>\n" );
document.write( "t = 2.7<BR>\n" );
document.write( "2.7 years<BR>\n" );
document.write( "Hope this helps :-) </SPAN>\n" );
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