document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1138573>Question 1138573</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A doctor prescribes 300 milligrams of a therapeutic drug that decays by about 17% each hour. To the nearest tenth, what is the half-life of the drug? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #756361 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=756361\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The decrease is 17% per hour or (0.83)^t, where t is number of hours.<BR>\n" );
document.write( "So want 0.5=0.83^t<BR>\n" );
document.write( "ln of both sides<BR>\n" );
document.write( "-0.693=t ln (0.83)<BR>\n" );
document.write( "t=3.719 hours or 3.7 hours </SPAN>\n" );
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