document.write( "Question 635359: A 20-gallon salt-water solution contains 15% pure salt. How much water should be added to make a new solution that is only 12% salt? \n" ); document.write( "

Algebra.Com's Answer #400266 by mananth(16946) $\"\"$ $\"About$

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20 gallons contains 15%\r
\n" ); document.write( "\n" ); document.write( "so it contains 3 grams salt. ((15/100) *20)\r
\n" ); document.write( "\n" ); document.write( "We need 12 % salt\r
\n" ); document.write( "\n" ); document.write( "so we have to add\r
\n" ); document.write( "\n" ); document.write( "(3*100)/12\r
\n" ); document.write( "\n" ); document.write( "=25 gallons\r
\n" ); document.write( "\n" ); document.write( "you have to add 25-20 = 5 gallons of water to make it 12% solution.\r
\n" ); document.write( "\n" ); document.write( "Alternative\r
\n" ); document.write( "\n" ); document.write( "-------------- percent ---------------- Amount
\n" ); document.write( "Salt solution 15 ---------------- 20 gallons
\n" ); document.write( "Water 0 ---------------- x gallons
\n" ); document.write( "Mixture 12 ---------------- 20 + x gallons
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\n" ); document.write( "15 * 20 + 0 x = 12 ( 20 + x )
\n" ); document.write( "300 + 0 x = 240 + 12 x
\n" ); document.write( "0 x -12 x = -300 + 240
\n" ); document.write( "-12 x = -60
\n" ); document.write( "/ -12
\n" ); document.write( "x = 5 gallons Water
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\n" ); document.write( "m.ananth@hotmail.ca \r
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