document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1057528>Question 1057528</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If P20,000 invested at interest compounded annually amounts to P21,218 in two years, what is the rate of interest? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #672572 by </B><A HREF=/tutors/aboutme.mpl?userid=math_helper><B>math_helper(2461)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=math_helper><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=math_helper><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=672572\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> We'll need the compound interest formula:\r<BR>\n" );
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document.write( "   <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+F+=+P+%281%2Br%2Fn%29%5E%28nt%29+ ALIGN=MIDDLE  ALT=\"+F+=+P+%281%2Br%2Fn%29%5E%28nt%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "—<BR>\n" );
document.write( "Where:  <BR>\n" );
document.write( "       F = future value (or final value)<BR>\n" );
document.write( "       P  = present value<BR>\n" );
document.write( "       n = number of compounding periods per year<BR>\n" );
document.write( "       r = rate, expressed as a decimal (so 4% is 0.04)<BR>\n" );
document.write( "       t = number of years<BR>\n" );
document.write( "—\r<BR>\n" );
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document.write( "We know:<BR>\n" );
document.write( "       P = 20000<BR>\n" );
document.write( "       F = 21218<BR>\n" );
document.write( "       t = 2 <BR>\n" );
document.write( "       n = 1   (compounds once per year)<BR>\n" );
document.write( "We need to solve for r\r<BR>\n" );
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document.write( "Plugging in these values gives:\r<BR>\n" );
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document.write( "     <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+21218+=+20000%281%2Br%2F1%29%5E%281%2A2%29+ ALIGN=MIDDLE  ALT=\"+21218+=+20000%281%2Br%2F1%29%5E%281%2A2%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "     <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+21218%2F20000+=+%281%2Br%29%5E2+ ALIGN=MIDDLE  ALT=\"+21218%2F20000+=+%281%2Br%29%5E2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "     <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+1.0609+=+%281%2Br%29%5E2+ ALIGN=MIDDLE  ALT=\"+1.0609+=+%281%2Br%29%5E2+\"   DISABLED_style= \"max-width:90%; height:auto;\" >     <BR>\n" );
document.write( "     <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+1.03+=+1%2Br+ ALIGN=MIDDLE  ALT=\"+1.03+=+1%2Br+\"   DISABLED_style= \"max-width:90%; height:auto;\" >               ( sqrt of both sides )<BR>\n" );
document.write( "     <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+r+=+0.03+ ALIGN=MIDDLE  ALT=\"+r+=+0.03+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "—<BR>\n" );
document.write( "Ans:  r = 3%<BR>\n" );
document.write( "—\r<BR>\n" );
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document.write( "Check:  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+20000%281%2B0.03%29%5E2++=+21218+ ALIGN=MIDDLE  ALT=\"+20000%281%2B0.03%29%5E2++=+21218+\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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