document.write( "Question 913873: how many liters of water should be added to 20 liters of a 70 percent antifreeze solution to make a 50 percent antifreeze solution?
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Algebra.Com's Answer #554780 by jim_thompson5910(35256)\"\" \"About 
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how many liters of water should be added to 20 liters of a 70 percent antifreeze solution to make a 50 percent acid solution?
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\n" ); document.write( "\n" ); document.write( "\"20 liters of a 70 percent antifreeze solution\" means we have\r
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\n" ); document.write( "\n" ); document.write( "20*0.70 = 14 liters of pure antifreeze
\n" ); document.write( "20-14 = 6 liters of pure water (alternate calculation: 20*0.3 = 6)\r
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\n" ); document.write( "\n" ); document.write( "Let x = amount of pure water to add\r
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\n" ); document.write( "\n" ); document.write( "We have 14 liters of pure antifreeze. This figure does NOT change when we add the pure water.\r
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\n" ); document.write( "\n" ); document.write( "We have 20 liters of solution. This gets bumped up to 20+x when we add the pure water.\r
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\n" ); document.write( "\n" ); document.write( "So we go from \"14%2F20\" to \"14%2F%2820%2Bx%29\". The fraction represents the percentage of antifreeze in the solution. \r
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\n" ); document.write( "\n" ); document.write( "We want this percentage to be 50%, so set the fraction equal to 0.50 and solve for x.\r
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document.write( "	\"14%2F%2820%2Bx%29=0.50\"\r\n" );
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document.write( "	\"14=0.50%2820%2Bx%29\"\r\n" );
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document.write( "	\"14=0.50%2820%29%2B0.50%28x%29\"\r\n" );
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document.write( "	\"14=10%2B0.50x\"\r\n" );
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document.write( "	\"14-10=0.50x\"\r\n" );
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document.write( "	\"4=0.50x\"\r\n" );
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document.write( "	\"4%2F0.50=x\"\r\n" );
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document.write( "	\"8=x\"\r\n" );
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document.write( "	\"x=8\"\r\n" );
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\n" ); document.write( "\n" ); document.write( "So you need to add 8 liters of pure water to make a 50 percent antifreeze solution.\r
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\n" ); document.write( "\n" ); document.write( "Let me know if you need more help or if you need me to explain a step in more detail.
\n" ); document.write( "Feel free to email me at jim_thompson5910@hotmail.com
\n" ); document.write( "or you can visit my website here: http://www.freewebs.com/jimthompson5910/home.html\r
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\n" ); document.write( "\n" ); document.write( "Thanks,\r
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\n" ); document.write( "\n" ); document.write( "Jim \n" ); document.write( "
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