document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1140194>Question 1140194</A>: <I><SPAN STYLE=\"word-break: break-all;\">  Question Help <BR>\n" );
document.write( "After the release of radioactive material into the atmosphere from a nuclear power plant in a country in 1990​, the hay in that country was contaminated by a radioactive isotope​ (half-life 5 ​days). If it is safe to feed the hay to cows when <BR>\n" );
document.write( "15​% of the radioactive isotope​ remains, how long did the farmers need to wait to use this​ hay?\r<BR>\n" );
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document.write( "__ days </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #760686 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39618)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><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=760686\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> x = 0 for year 1990\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=pe%5E%28-kx%29 ALIGN=MIDDLE  ALT=\"y=pe%5E%28-kx%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=ln%281%2F2%29=-5k ALIGN=MIDDLE  ALT=\"ln%281%2F2%29=-5k\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=k=ln%282%29%2F5 ALIGN=MIDDLE  ALT=\"k=ln%282%29%2F5\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=pe%5E%28-.1386x%29 ALIGN=MIDDLE  ALT=\"y=pe%5E%28-.1386x%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "----<BR>\n" );
document.write( "If it is safe to feed the hay to cows when <BR>\n" );
document.write( "15​% of the radioactive isotope​ remains, how long did the farmers need to wait to use this​ hay? <BR>\n" );
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document.write( "Solve for x with  <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0.15=e%5E%28-0.1386x%29 ALIGN=MIDDLE  ALT=\"0.15=e%5E%28-0.1386x%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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