document.write( "Question 1128980: A 2.5 L container has a mixture of 25% alcohol. How many liters of the mixture must be drained out and replaced with pure alcohol in order to obtain a mixture containing 40% alcohol? \n" ); document.write( "

Algebra.Com's Answer #745509 by ikleyn(52800) $\"\"$ $\"About$

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document.write( "Let W be the volume to drain off from 2.5 liters of the original mixture.\r\n" );
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document.write( "Step 1:  Draining.  After draining,  you have 2.5-W liters of the 25% mixture.\r\n" );
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document.write( "Step 2:  Replacing.  Then you add W liters of the pure alcohol (the replacing step).\r\n" );
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document.write( "                     After the replacing,  you have the same total liquid volume of 2.5 liters.\r\n" );
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document.write( "It contains  0.25(2.5-W) + W  of the pure alcohol.\r\n" );
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document.write( "So, your \"concentration equation\" is\r\n" );
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document.write( " = 0.4.    (1)\r\n" );
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document.write( "The setup is done and completed.\r\n" );
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document.write( "Now you need to solve your basic equation  (1).\r\n" );
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document.write( "0.25*(2.5-W) + W = 0.4*2.5\r\n" );
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document.write( "0.25*2.5 - 0.25W + W = 0.4*2.5\r\n" );
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document.write( "0.75W = 1 - 0.625\r\n" );
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document.write( "W =  = 0.5.\r\n" );
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document.write( "Answer.  0.5  of a liter of the original mixture should be drained and replaced with the pure alcohol.\r\n" );
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\n" ); document.write( "\n" ); document.write( "There is entire bunch of lessons covering various types of mixture problems\r
\n" ); document.write( "\n" ); document.write( "    - Mixture problems\r
\n" ); document.write( "\n" ); document.write( "    - More Mixture problems\r
\n" ); document.write( "\n" ); document.write( "    - Solving typical word problems on mixtures for solutions \r
\n" ); document.write( "\n" ); document.write( "    - Word problems on mixtures for antifreeze solutions \r
\n" ); document.write( "\n" ); document.write( "    - Word problems on mixtures for dry substances like coffee beans, nuts, cashew and peanuts\r
\n" ); document.write( "\n" ); document.write( "    - Word problems on mixtures for dry substances like candies, dried fruits\r
\n" ); document.write( "\n" ); document.write( "    - Word problems on mixtures for dry substances like soil and sand\r
\n" ); document.write( "\n" ); document.write( "    - Word problems on mixtures for alloys \r
\n" ); document.write( "\n" ); document.write( "    - Typical word problems on mixtures from the archive\r
\n" ); document.write( "\n" ); document.write( "    - Advanced mixture problems \r
\n" ); document.write( "\n" ); document.write( "    - Advanced mixture problem for three alloys \r
\n" ); document.write( "\n" ); document.write( "    - OVERVIEW of lessons on word problems for mixtures\r
\n" ); document.write( "\n" ); document.write( "in this site.\r
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\n" ); document.write( "\n" ); document.write( "A convenient place to quickly observe these lessons from a \"bird flight height\" (a top view) is the last lesson in the list.\r
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\n" ); document.write( "\n" ); document.write( "Read them and become an expert in solution the mixture word problems.\r
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\n" ); document.write( "\n" ); document.write( "Also, you have this free of charge online textbook in ALGEBRA-I in this site\r
\n" ); document.write( "\n" ); document.write( "    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.\r
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\n" ); document.write( "\n" ); document.write( "The referred lessons are the part of this online textbook under the topic \"Mixture problems\".\r
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\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Save the link to this online textbook together with its description\r
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\n" ); document.write( "\n" ); document.write( "Free of charge online textbook in ALGEBRA-I
\n" ); document.write( "https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson\r
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\n" ); document.write( "\n" ); document.write( "to your archive and use it when it is needed.\r
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