document.write( "Question 940466: How many quarts of pure antifreeze must be added to 7 quarts of 10% antifreeze solution to obtain a 20% antifreeze solution? \n" ); document.write( "

Algebra.Com's Answer #573167 by macston(5194) $\"\"$ $\"About$

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It is best to consider the part of the problem that is not changing, the amount of water. In 7 quarts of a 10% antifreeze (90% water) solution there is
\n" ); document.write( "0.90(7 quarts)=6.3 quarts of water. To make a 20% solution (80% water)with 6.3 quarts of water, we need 6.3/.80=7.875 quarts total. So to make 7 quarts of 10% solution 20% we must add 0.875 quarts of pure antifreeze to make a total of 7.875 quarts. \n" ); document.write( "

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