document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1198803>Question 1198803</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Radon is a naturally occurring radioactive gas which can collect in poorly ventilated structures. Radon gas is formed by the decomposition of radium-226 which has a half life of 1622 years. The half-life of radon is 3.82 days. Suppose a house basement contained 38 grams of radon gas when a family moved in. If the source of radium producing the radon gas is removed so that the radon gas eventually decays, how long will it take until there is only 6.8 grams of radon gas present? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #832465 by </B><A HREF=/tutors/aboutme.mpl?userid=ikleyn><B>ikleyn(52803)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ikleyn><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=ikleyn><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=832465\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> .\r<BR>\n" );
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document.write( "How @Theo solves this problem, &nbsp;is &nbsp;WRONG &nbsp;TEACHING.\r<BR>\n" );
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document.write( "The standard method for this formulation is shown in the post by @math_tutor2020.\r<BR>\n" );
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document.write( "It is short, straightforward and &nbsp;EXCLUDES &nbsp;100 &nbsp;tons of unnecessary calculations<BR>\n" );
document.write( "that @Theo makes in his post.\r<BR>\n" );
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document.write( "<PRE STYLE=\"white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;\">\r\n" );
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document.write( "    |           When the problem gives the-half life duration,                |\r\n" );
document.write( "    |         the correct analytic solution of  a  decay problem              |\r\n" );
document.write( "    |    MUST be started from writing exponential decay function base 1/2,    |\r\n" );
document.write( "    | if the opposite is not requested by the problem directly and explicitly.|\r\n" );
document.write( "    |                                                                         |\r\n" );
document.write( "    |    So called \"ekt-form\" is IRRELEVANT in such cases, so avoid use it,   |\r\n" );
document.write( "    |             if you do not want to appear incompetent.                   |\r\n" );
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document.write( "</PRE>\r<BR>\n" );
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document.write( "See also my lesson on radioactive decay problems under the link\r<BR>\n" );
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document.write( "&nbsp;&nbsp;&nbsp;&nbsp;- <A  rel=nofollow HREF=https://www.algebra.com/algebra/homework/logarithm/Radioactive-decay-problems.lesson>Radioactive decay problems</A> \r<BR>\n" );
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document.write( "in this site.\r<BR>\n" );
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document.write( "You will find many similar &nbsp;(and different) &nbsp;solved problems there.\r<BR>\n" );
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document.write( "This problem should be and must be solved in &nbsp;5 - 6 - 7 &nbsp;lines, &nbsp;no more than that.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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