document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1172281>Question 1172281</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An automobile radiator contains 18 quarts of a solution which is 20% alcohol and 80% water. How much of the solution <BR>\n" );
document.write( "must be drained off and replace by pure alcohol to give a solution which is 30 alcohol? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #797284 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13203)</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=797284\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "The \"drained off...\" and \"replaced by...\" language is only used to confuse you.<br><BR>\n" );
document.write( "Essentially the problem is just mixing 20% alcohol and 100% alcohol to get 30% alcohol.<br><BR>\n" );
document.write( "For a quick and easy non-algebraic method for solving the problem, note that you are starting with a 20% alcohol solution and adding 100% alcohol, stopping when you get to 30% alcohol.<br><BR>\n" );
document.write( "With that way of thinking of the problem, observe that 30% is 1/8 of the way from 20% to 100% (20 to 30 is 10; 20 to 100 is 80; 10/80 = 1/8); that means 1/8 of the final mixture is the added 100% alcohol.<br><BR>\n" );
document.write( "Since the capacity of the radiator is 18 quarts, the amount of 100% alcohol in the mixture is 18/8 = 2.25 quarts.<br><BR>\n" );
document.write( "ANSWER: 2.25 quarts of the original solution must be drained off and replaced by 100% alcohol to obtain 18 quarts of 30% alcohol.<br><BR>\n" );
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