document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=482244>Question 482244</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A computer is infected with a virus.  Assume that it infects 20 other computers within 5 minutes; and that these PCs and servers each infect 20 more machines within another five minutes, etc.  How long until 100 million computers are infected? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #330160 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=330160\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A computer is infected with a virus. Assume that it infects 20 other computers within 5 minutes; and that these PCs and servers each infect 20 more machines within another five minutes, etc. How long until 100 million computers are infected?<BR>\n" );
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document.write( "start: 1<BR>\n" );
document.write( "5 min: 1*20 = 20<BR>\n" );
document.write( "2*5 min: 20*20 = 20^2<BR>\n" );
document.write( "3*5 min: 20^3<BR>\n" );
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document.write( "x min : 20^(x/5)<BR>\n" );
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document.write( "Solve 20^(x/5) = 100 million = 10^8<BR>\n" );
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document.write( "(x/5)log(20) = 8<BR>\n" );
document.write( "(x/5) = 6.149<BR>\n" );
document.write( "x = 30.75 minutes<BR>\n" );
document.write( "=========================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "=========================  </SPAN>\n" );
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