document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1200225>Question 1200225</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Last year, Carlos had $30,000 to invest. He invested some of it in account that paid 10% simple interest per year, and he invested the rest in an account that paid 5% simple interest per year. After one year, he received a total of $2500 in interest. How much did he invest in each account?<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #834289 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=834289\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "With formal algebra....<br><BR>\n" );
document.write( "x = amount invested at 10%<BR>\n" );
document.write( "30000-x = amount at 5%<br><BR>\n" );
document.write( "The total interest was $2500:<br><BR>\n" );
document.write( ".10(x)+.05(30000-x) = 2500<br><BR>\n" );
document.write( "Solve using basic algebra... I leave that to you.<br><BR>\n" );
document.write( "Informally, if a formal algebraic solution is not required....<br><BR>\n" );
document.write( "All $30000 invested at 5% would have returned $1500 interest; all at 10% would have returned $3000 interest.<BR>\n" );
document.write( "The actual interest $2500 is 2/3 of the way from $1500 to $3000.<BR>\n" );
document.write( "That means 2/3 of the total was invested at the higher rate.<br><BR>\n" );
document.write( "ANSWER: 2/3 of the $30000, or $20000, at 10%; the other $10000 at 5%<br><BR>\n" );
document.write( "CHECK: .10($20000)+.05($10000) = $2000+$500 = $2500<br><BR>\n" );
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