document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1170820>Question 1170820</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A population of lizards is growing at a rate of 4.6% / year. Initially, there are 1750 lizards. How long will it take for the population to double? (round to two decimal places)\r<BR>\n" );
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document.write( "A.14.72 years\r<BR>\n" );
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document.write( "B.16.21 years\r<BR>\n" );
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document.write( "C.15.41 years\r<BR>\n" );
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document.write( "D.Solution not listed\r<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #795701 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=795701\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Rule of 70 (70/4.6=15.22) suggests C<BR>\n" );
document.write( "3500=1750(1.046)^n<BR>\n" );
document.write( "2=1.046^n<BR>\n" );
document.write( "ln2=n ln 1.046 <BR>\n" );
document.write( "0.693/0.0445=n.  The 0.693 is the decimal of 69.3%, and that is why the Rule of 70 exists for doubling. Some use 72, since so many more numbers divide evenly into it.<BR>\n" );
document.write( "n=15.41 years.<BR>\n" );
document.write( "C </SPAN>\n" );
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