document.write( "Question 386566: A hospital needs 40 L of a solution of disinfectant. How many liters of a 20% solution and a 4% solution should be mixed to obtain this 15% solution? \n" ); document.write( "

Algebra.Com's Answer #273278 by ewatrrr(24785) $\"\"$ $\"About$

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document.write( "Hi,         
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document.write( "Let x and (40L-x) represent the 20% and 4% solutions respectively
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document.write( "Mixing the 20% and 1%  to form 40L of 15% solution
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document.write( " .20x + .04(40L-x) = .15*40L
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document.write( "              .16x = .11*40L
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document.write( "                 x = .11*40L/.16
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document.write( "                 x = 27.5L, the amount of the 20% solution.  
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document.write( "                     12.5L,the amount of the 4% solution  (40L - 27.5L)
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document.write( "CHECKING our Answer
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document.write( " .20*27.5L + .04*12.5L = 5.5L + .5L = 6L = .15*40L
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document.write( "Which tells us incidentally there is 6L of disinfectant in the final solution. \n" );
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