document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=979496>Question 979496</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A culture starts with 9000 bacteria. After one hour the count is 10,000.<BR>\n" );
document.write( "(a) Find a function that models the number of bacteria n(t) after t hours. (Round your r value to three decimal places.)<BR>\n" );
document.write( "n(t) =<BR>\n" );
document.write( "b. How many hours will the number of bacteria double? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #600784 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=600784\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A=Ao{1+r}^t; t=hours<BR>\n" );
document.write( "10000=9000(l+r)^t<BR>\n" );
document.write( "divide by 9000 and take ln of both sides<BR>\n" );
document.write( "ln (10/9)=t ln (1+r)<BR>\n" );
document.write( "0.1054=ln(1+r)<BR>\n" );
document.write( "raise both sides to e power<BR>\n" );
document.write( "1.111=1+r<BR>\n" );
document.write( "r=0.111 or 11.1%\r<BR>\n" );
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document.write( "ln2=t ln (1.111)<BR>\n" );
document.write( "0.693=t * 0.10536<BR>\n" );
document.write( "t=6.578 hours or about 6 hours 35 minutes\r<BR>\n" );
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document.write( "Check:<BR>\n" );
document.write( "1.111^6.578=2\r<BR>\n" );
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document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );