document.write( "Question 662267: A radiator contains 15 quarts of fluid, 30% of which is antifreeze. How much fluid should be drained and replaced with pure antifreeze so that the new mixture is 55% antifreeze? \n" ); document.write( "

Algebra.Com's Answer #412065 by Edwin McCravy(20056) $\"\"$ $\"About$

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A radiator contains 15 quarts of fluid, 30% of which is antifreeze. How much fluid should be drained and replaced with pure antifreeze so that the new mixture is 55% antifreeze?
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document.write( "When we drain out x quarts there will only be 15-x quarts left in there.\r\n" );
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document.write( "30% of those 15-x quarts is pure antifreeze. So that's .30(15-x) quarts \r\n" );
document.write( "of pure antifreeze in there after we have drained off x quarts.\r\n" );
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document.write( "Now we replace those x quarts with pure antifreeze.  Now the amount\r\n" );
document.write( "of pure antifreeze is .30(15-x)+x quarts.  There are 15 quarts of liquid\r\n" );
document.write( "in the radiator, so the fraction of the 15 quarts that is pure antifreeze\r\n" );
document.write( "is this fraction:  \r\n" );
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document.write( "               \r\n" );
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document.write( "And that fraction is to be equal to 55% or .55\r\n" );
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document.write( "                = .55\r\n" );
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document.write( "Multiply both sides by 15\r\n" );
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document.write( "               .30(15-x)+x = 8.25\r\n" );
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document.write( "Solve that and get  or  quarts.\r\n" );
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document.write( "Edwin

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