document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1167264>Question 1167264</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Larry mitchel invested part of his $13,000 advance at 7% annual simple interest and the rest at 3% annual simple interest. If his total yearly interest from both accounts was $870, find the amount invested at each rate </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #791903 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13198)</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=791903\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "Here is a non-algebraic method for solving a \"mixture\" problem like this.<br><BR>\n" );
document.write( "(1) Find the amounts of interest if the whole $13,000 had been invested at each rate.<br><BR>\n" );
document.write( "$13,000 at 7% would yield $910 interest; $13,000 at 3% would yield $390 interest.<br><BR>\n" );
document.write( "(2) Where the actual interest lies between those two amounts exactly determines how much was invested at each rate.<br><BR>\n" );
document.write( "From 390 to 910 on a number line is a difference of 520; from 390 to 870 is a difference of 480.  480/520 = 48/52 = 12/13.<br><BR>\n" );
document.write( "$870 is 12/13 of the way from $390 to $910; that means 12/13 of the total was invested at the higher rate.<br><BR>\n" );
document.write( "ANSWERS: 12/13 of $13,000, or $12,000, was invested at 7%; the other $1000 was invested at 3%.<br><BR>\n" );
document.write( "CHECK: .07(12000)+.03(1000) = 840+30 = 870<br><BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );