document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=484542>Question 484542</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Can you help me answer this: A car radiator contains 10 liters of 30% solution.  How many liters will have to be replaced with pur antifreeze if the resulting solution is to be 50% antifreeze?\r<BR>\n" );
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document.write( "Is 4 liters correct? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #331534 by </B><A HREF=/tutors/aboutme.mpl?userid=chessace><B>chessace(471)</B></A><img src=\"/images/stars/stars-10.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=chessace><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=chessace><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=331534\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Nope.<BR>\n" );
document.write( "As usual x = amount replaced.<BR>\n" );
document.write( "You are going to take out x which consists of .3 AF (and .7 not).<BR>\n" );
document.write( "Then put in x of all AF.<BR>\n" );
document.write( "Required: 50% AF after this operation.<BR>\n" );
document.write( "I.e., new + old AF = 50 % of 10 liters = 5 liters.<BR>\n" );
document.write( "The old AF is the amount in middle of operation * its % AF<BR>\n" );
document.write( "Mid amount: 10 - x, AF still 30% or .3<BR>\n" );
document.write( "x + (10 - x) * .3 = 5<BR>\n" );
document.write( "x + 10*0.3 - .3 x = 5<BR>\n" );
document.write( "(1-0.3)x + 3 = 5<BR>\n" );
document.write( ".7 x = 5 - 3<BR>\n" );
document.write( "7 x = 20<BR>\n" );
document.write( "x = 20/7 liters [< 3]<BR>\n" );
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