document.write( "Question 1112659: We would like to create 20 gallons of solution that is 25% acid. How many gallons each, of a
\n" ); document.write( "10% acid solution and a 30% acid solution would we mix? \n" ); document.write( "

Algebra.Com's Answer #727702 by ikleyn(52787) $\"\"$ $\"About$

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\n" ); document.write( "You can solve the problem algebraically and/or intuitively.\r
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\n" ); document.write( "\n" ); document.write( "Intuitive solution is this:\r
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document.write( "    On each gallon of the 10% solution take 3 gallons of the 30% solution.\r\n" );
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document.write( "    It works, since   =  = 0.25 = 25%.\r\n" );
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document.write( "    Thus you get 5 groups/packages each containing (1 gallon of the 10% solution PLUS 3 gallons of the 30% solutions),\r\n" );
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document.write( "    which gives you 5 gallons of the 10% solution AND 15 gallons of the 30% solutions, in all.\r\n" );
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\n" ); document.write( "\n" ); document.write( "Algebraic solution is this:\r
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document.write( "     = 0.25.\r\n" );
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document.write( "    saying that the concentration of the mixture is 25% = 0.25.\r\n" );
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document.write( "    The steps to solve it are\r\n" );
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document.write( "        0.1x +0.3*(20-x) = 0.25*20\r\n" );
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document.write( "        0.1x + 6 - 0.3x = 5\r\n" );
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document.write( "        -0.2x = 4 - 5 = -1  ====>  x =  = 5.\r\n" );
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document.write( "    You get the same answer:  5 gallons of the 10% solution and (20-5) = 15 gallons of the 30% solution.\r\n" );
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