document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1040087>Question 1040087</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A scientist determined that the bones from a mastodon had lost 70.2% of their carbon-14.How old were the bones at the time they were&#8203; discovered? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #654874 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=654874\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> It is [ln(.298)/-0.693]*5730=1.747*5730=10010.2 years<BR>\n" );
document.write( "-0.693 is ln (1/2), the half life, or 50%. If 75% were lost, that would be 2 half-lives or 11460 years, so this is in the range. <BR>\n" );
document.write( "Determine the number of half life (1/2)^n=0.298<BR>\n" );
document.write( "ln of both sides is n ln(1/2)=ln 0.298.  Divide both sides by ln (1/2), which is -0.693 </SPAN>\n" );
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