document.write( "Question 1102100: A 20% solution of fertilizer is to be mixed with a 50% solution of fertilizer in order to get 60 gallons of a 40% solution. How many gallons of the 20% and 50% solution should be mixed? \n" ); document.write( "
Algebra.Com's Answer #716739 by richwmiller(17219)\"\" \"About 
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Let A denote the 50% solution and B denote the 20% solution which we have.
\n" ); document.write( "Let C denote the 40% solution which we want.
\n" ); document.write( "Using the method of alligation.
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document.write( "50         20 20/30*60=40 gal of 50% solution\r\n" );
document.write( "      40     40+20= 60 gal of 40% solution\r\n" );
document.write( "20         10 10/30*60=20 gal of 20% solution\r\n" );
document.write( "           30\r\n" );
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\n" ); document.write( "10= 50 - 40
\n" ); document.write( "20= 40 - 20
\n" ); document.write( "20+10=30 parts total
\n" ); document.write( "There are 60 gal total
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document.write( "50         20 20/30*60=40 gal of 50% solution\r\n" );
document.write( "

\n" ); document.write( "20/30*60=40
\n" ); document.write( "40 gal of 50% solution.
\n" ); document.write( "60-40=20 gal
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document.write( "20         10 10/30*60=20 gal of 20% solution\r\n" );
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\n" ); document.write( "20 gal of 20% solution.\r
\n" ); document.write( "\n" ); document.write( "check
\n" ); document.write( "0.2 * 20 + 0.5 * 40 = 0.4*60
\n" ); document.write( "4.0 + 20.0 = 24.0
\n" ); document.write( "24.0 = 24.0
\n" ); document.write( "ok\r
\n" ); document.write( "\n" ); document.write( "Now using algebra
\n" ); document.write( "We need a total of 60 gal at 40%
\n" ); document.write( "We want to know how many gal at 20% to mix with 50%
\n" ); document.write( "a+b=60
\n" ); document.write( "0.2*a+0.5*b=0.4*60
\n" ); document.write( "a=60-b
\n" ); document.write( "0.2*(60-b)+0.5*b=24
\n" ); document.write( "12-0.2b+0.5*b=24
\n" ); document.write( "0.3*b=12
\n" ); document.write( "b=40
\n" ); document.write( "a=60-b
\n" ); document.write( "a=20 gal at 20%
\n" ); document.write( "b=40 gal at 50%
\n" ); document.write( "check
\n" ); document.write( "0.2*20+0.5*40=0.4*60
\n" ); document.write( "4+20=24
\n" ); document.write( "24=24
\n" ); document.write( "ok
\n" ); document.write( "codemx1
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