document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=402769>Question 402769</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I would really appreciate some help with this one.\r<BR>\n" );
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document.write( "The half life of a radio active substance is 125 days. How many days will it take for 82% of the substance to decay?\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 #284962 by </B><A HREF=/tutors/aboutme.mpl?userid=scott8148><B>scott8148(6628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=scott8148><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=scott8148><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=284962\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> At = Ao (1/2)^(t/h) ___ At is amount at time t ; Ao is initial amount ; t is the time ; h is the half life\r<BR>\n" );
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document.write( "At / Ao = (1/2)^(t/h)\r<BR>\n" );
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document.write( "1 - .82 = (1/2)^(t/125)\r<BR>\n" );
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document.write( "log(.18) = (t/125)log(1/2)\r<BR>\n" );
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document.write( "[log(.18)] / [log(1/2)] = t / 125 </SPAN>\n" );
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