document.write( "Question 763949: A radiator contains 10 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 40% antifreeze? \n" ); document.write( "

Algebra.Com's Answer #465130 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+x+\"$ = quarts of fluid to be drained and replaced
\n" ); document.write( "with pure antifreeze
\n" ); document.write( " $\"+.3x+\"$ = quarts of pure antifreeze in fluid drained off
\n" ); document.write( " $\"+.3%2A10+=+3+\"$ quarts of pure antifreeze originally in fluid
\n" ); document.write( "----------------------------
\n" ); document.write( " $\"+%28+3+-+.3x++%2B+x+%29+%2F+10+=+.4+\"$
\n" ); document.write( "( note that you start with $\"+10+\"$ quarts and end with $\"+10+\"$ quarts )
\n" ); document.write( " $\"+%28+3+%2B+.7x+%29+%2F+10+=+.4+\"$
\n" ); document.write( " $\"+3+%2B+.7x+=+4+\"$
\n" ); document.write( " $\"+.7x+=+1+\"$
\n" ); document.write( " $\"+x+=+1.4286+\"$
\n" ); document.write( "1.4286 quarts of fluid must be drained off and
\n" ); document.write( "replaced with pure antifreeze
\n" ); document.write( "check:
\n" ); document.write( " $\"+%28+3+-+.3x++%2B+x+%29+%2F+10+=+.4+\"$
\n" ); document.write( " $\"+%28+3+-+.3%2A1.4286++%2B+1.4286+%29+%2F+10+=+.4+\"$
\n" ); document.write( " $\"++3+-+.4286+%2B+1.4286+=+4+\"$
\n" ); document.write( " $\"+4+=+4+\"$
\n" ); document.write( "OK
\n" ); document.write( " \n" ); document.write( "

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