document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1161939>Question 1161939</A>: <I><SPAN STYLE=\"word-break: break-all;\"> To make a 6% acid solution, a chemist mixes some 4% acid solution with 12 L of 10% acid solution. How much of the 4% solution must be added to the 10% solution to make the 6% acid solution? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #785601 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=785601\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "A typical setup for solving the problem using formal algebra....<br><BR>\n" );
document.write( "10% of the 12L you start with, plus 4% of the x L you add, yields 6% of the (12+x) L:<br><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=.10%2812%29%2B.04%28x%29+=+.06%2812%2Bx%29 ALIGN=MIDDLE  ALT=\".10%2812%29%2B.04%28x%29+=+.06%2812%2Bx%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><br><BR>\n" );
document.write( "Solve using basic algebra....<br><BR>\n" );
document.write( "If a formal algebraic solution is not required, here is a quick and easy way to solve mixture problems like this....<br><BR>\n" );
document.write( "You are starting with 10% acid and adding 4% acid until the solution is 6% acid.<br><BR>\n" );
document.write( "Model that by imagining walking on a number line from 10 towards 4, stopping when you get to 6.  What fraction of the distance have you gone?<br><BR>\n" );
document.write( "From 10 to 4 is a distance of 6; from 10 to 6 is a distance of 4.  The fraction of the distance you have gone is 4/6 = 2/3.<br><BR>\n" );
document.write( "That means 2/3 of the final mixture is what you are adding.<br><BR>\n" );
document.write( "So the 12L you started with is 1/3 of the final mixture; and that means the amount of 4% acid you added (2/3 of the final mixture) was 24L.<br><BR>\n" );
document.write( "ANSWER: 24L<br><BR>\n" );
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