document.write( "Question 1033124: A certain quantity was taken from a ten liter 30% alcohol solution and replaced by pure alcohol so as to produce 51% alcohol solution. How many liters were taken and replaced? \n" ); document.write( "

Algebra.Com's Answer #647734 by ikleyn(52786) $\"\"$ $\"About$

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\n" ); document.write( "A certain quantity was taken from a ten liter 30% alcohol solution and replaced by pure alcohol so as
\n" ); document.write( "to produce 51% alcohol solution. How many liters were taken and replaced?
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document.write( "Let \"x\" be the volume of the 30% alcohol solution taken from and replaced.\r\n" );
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document.write( "After replacement, we have the same volume of 10 liters of the (new) solution.\r\n" );
document.write( "The alcohol content in the new solution is x + 0.3*(10-x).\r\n" );
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document.write( "Since it is 10 liter of the 51% of alcohol solution, you have this equation\r\n" );
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document.write( "x + 0.3*(10-x) = 0.51*10.\r\n" );
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document.write( "Simplify and solve for x:\r\n" );
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document.write( "x + 3 - 0.3x = 5.1,\r\n" );
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document.write( "0.7x = 5.1 - 3,\r\n" );
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document.write( "0.7x = 2.1,\r\n" );
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document.write( "x =  = 3.\r\n" );
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document.write( "Answer.  3 liters of the original solution were taken off and replaced by the pure alcohol.\r\n" );
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