document.write( "Question 213388: how many gallons of pure alcohol should b mixed with 20 gallons of a 15% alchol solution to obtain a mixture that is 25% alcohol? \n" ); document.write( "
Algebra.Com's Answer #161177 by stanbon(75887)\"\" \"About 
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how many gallons of pure alcohol should be mixed with 20 gallons of a 15% alcohol solution to obtain a mixture that is 25% alcohol?
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\n" ); document.write( "alcohol + alcohol = alcohol
\n" ); document.write( "0.15*20 + x = 0.25(20+x)
\n" ); document.write( "Multiply thru by 100 to get:
\n" ); document.write( "15*20 + 100x = 25*20 + 25x
\n" ); document.write( "75x = 10*20
\n" ); document.write( "x = 2 2/3 gallons (amount of 100% alcohol needed for the mixture)
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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