document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=262094>Question 262094</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A chemical sample contains 23 mg of a radioactive substance. 4 hours ago it contained 25mg. how many grams will the sample contain four hours from now? 8 hours?<BR>\n" );
document.write( "formula: A(t)=Ao(1+r)^(t/f)<BR>\n" );
document.write( "so I am guessing this: A(t)=25(23/25)^(t/4)and A(t)=25(23/25)^(t/8) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #193094 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=193094\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  A chemical sample contains 23 mg of a radioactive substance. 4 hours ago it contained 25mg. how many grams will the sample contain four hours from now? 8 hours?<BR>\n" );
document.write( "formula: A(t)=Ao(1+r)^(t/f)<BR>\n" );
document.write( "so I am guessing this: A(t)=25(23/25)^(t/4)and A(t)=25(23/25)^(t/8)<BR>\n" );
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document.write( "Almost right.  If t=0 is the present time, then you have to start with the 23 mg that are left.<BR>\n" );
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document.write( "A(4)=23(23/25)^(4/4) = 21.16 mg and <BR>\n" );
document.write( "A(8)=23(23/25)^(8/4) = 19.4672 mg<BR>\n" );
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