document.write( "Question 101977: A car radiator has a capacity of 16qts and is filled w/a 25% antifreeze solution. How much must be drained off and replaced w/pure antifreeze to obtain a 40% antifreeze solution? \n" ); document.write( "
Algebra.Com's Answer #74343 by ankor@dixie-net.com(22740)\"\" \"About 
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A car radiator has a capacity of 16 qts and is filled w/a 25% anti-freeze solution. How much must be drained off and replaced w/pure antifreeze to obtain a 40% anti-freeze solution?
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\n" ); document.write( "Let x = the amt drained and the amt added
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\n" ); document.write( "Drained + Added = required mixture
\n" ); document.write( ".25(16-x) + 1.0x = .40(16)
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\n" ); document.write( "4 - .25x + 1x = .40(16)
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\n" ); document.write( "4 + .75x = 6.4
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\n" ); document.write( ".75x = 6.4 - 4
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\n" ); document.write( ".75x = 2.4
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\n" ); document.write( "x = 2.4/.75
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\n" ); document.write( "x = 3.2 gal of pure antifreeze
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\n" ); document.write( "Check solution using x = 3.2:
\n" ); document.write( ".25(16-3.2) + 3.2 = .40(16)
\n" ); document.write( ".25(12.8) + 3.2 = 6.4
\n" ); document.write( " 3.2 + 3.2 = 6.4 \n" ); document.write( "
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