document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1195905>Question 1195905</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A total of $9000 is invested: part at 5% and the remainder at 15%. How much is invested at each rate if the annual interest is $520? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #828528 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13200)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=greenestamps><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=greenestamps><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=828528\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "Here is an informal method for solving this kind of problem that is fast and easy if the numbers are \"nice\".<br><BR>\n" );
document.write( "(1) All $9000 invested at 5% would earn $450 interest; all at 15% would earn $1350 interest.<BR>\n" );
document.write( "(2) Perhaps using a number line, look where the actual interest of $520 lies between $450 and $1350: 450 to 520 is a difference of 70; 450 to 1350 is a difference of 900; 520 is 70/900 = 7/90 of the way from 450 to 1350.<BR>\n" );
document.write( "(3) That means 7/90 of the total was invested at the higher rate.<br><BR>\n" );
document.write( "ANSWER: 7/90 of $9000, or $700, was invested at 15%; the other $8300 at 5%.<br><BR>\n" );
document.write( "CHECK: .05(8300)+.15(700) = 415+105 = 520<br><BR>\n" );
document.write( " </SPAN>\n" );
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