document.write( "Question 658888: A tank holds 140 liters of checmical solution. Currently the solution has a strength of 60%. How much of this should be drained and replaced with 100% solution to get a final strength of 80%? \n" ); document.write( "

Algebra.Com's Answer #410540 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
For clarity, I'll just suppose the solution
\n" ); document.write( "is water plus antifreeze, so it's 60%
\n" ); document.write( "antifreeze.
\n" ); document.write( "--------------------
\n" ); document.write( "given:
\n" ); document.write( " $\"+.6%2A140+=+84+\"$ liter of antifreeze in 60% solution
\n" ); document.write( "Let $\"+x+\"$ = liters of 60% antifreeze to be drained
\n" ); document.write( "and repaced with 100% antifreeze
\n" ); document.write( "( note there is 140 liters when you start
\n" ); document.write( "and 140 liters when you finish )
\n" ); document.write( "--------------------
\n" ); document.write( " $\"+%28+84+-+.6x+%2B+x+%29+%2F+140+=+.8+\"$
\n" ); document.write( " $\"+84+%2B+.4x+=+.8%2A140+\"$
\n" ); document.write( " $\"+84+%2B+.4x+=+112+\"$
\n" ); document.write( " $\"+.4x+=+28+\"$
\n" ); document.write( " $\"+x+=+70+\"$
\n" ); document.write( "70 liters of solution must be drained and
\n" ); document.write( "replaced with 100% solution \n" ); document.write( "

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