document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1017355>Question 1017355</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a 30 quart cooling system is checked and found to be filled with a solution that is 40% antifreeze. The desired strength of the solution is 60% antifreeze. How many quarts of solution need to be drained and replaced with pure antifreeze to reach the desired strength? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #633650 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=633650\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 40% antifreeze in 30 quarts equals 12 quarts of pure antifreeze.<BR>\n" );
document.write( "60% antifreeze in 30 quarts equals 18 quarts of pure antifreeze.\r<BR>\n" );
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document.write( "you need to pour out x number of quarts of 40% antifreeze and replace them with x quarts of 100% antifreeze to get a solution that is 30 quarts of 60% antifreeze.\r<BR>\n" );
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document.write( "each quart that you replace with 100% antifreeze loses you 40% antifreeze, so you get a net gain of 60% antifreeze for each quart that you replace.\r<BR>\n" );
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document.write( "you need 6 quarts of pure antifreeze.<BR>\n" );
document.write( "in order to gain 6 quarts of pure antifreeze, you need to add 6/.6 = 10 quarts of 60% antifreeze.\r<BR>\n" );
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document.write( "you will then have a solution that is 60% antifreeze.\r<BR>\n" );
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document.write( "here's how it works.\r<BR>\n" );
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document.write( "you have 30 quarts of 40% antifreeze.<BR>\n" );
document.write( "you remove 10 quarts of 40% antifreeze and replace them with 10 quarts of 100% antifreeze.\r<BR>\n" );
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document.write( "you are left with 20 quarts of 40% antifreeze and 10 quarts of 100% antifreeze.\r<BR>\n" );
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document.write( "the 20 quarts of 40% antifreeze give you .4 * 20 = 8 quarts of pure antifreeze.<BR>\n" );
document.write( "add the 10 quarts of pure antifreeze to that and you have a total of 18 quarts of pure antifreeze in a 30 quart solution.\r<BR>\n" );
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document.write( "the percent antifreeze is now 18/30 = .6 = 60%.\r<BR>\n" );
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document.write( "your solution is that you need to drain 10 quarts of antifreeze and replace them with 10 quarts of pure antifreeze to get 30 quarts of 60% antifreeze.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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