document.write( "Question 513002: how many liters of pure alcohol must be added to 15 liters of 20% solution to obtain a mixture which is 30 % alcohol? \n" ); document.write( "
Algebra.Com's Answer #342834 by Maths68(1474)\"\" \"About 
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Solution A
\n" ); document.write( "Amount = x
\n" ); document.write( "Concentration = 100%=1
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\n" ); document.write( "Solution B
\n" ); document.write( "Amount = 15
\n" ); document.write( "Concentration = 20%=0.2
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\n" ); document.write( "Solution Final
\n" ); document.write( "Amount=15+x
\n" ); document.write( "Concentraction = 30% =0.3\r
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\n" ); document.write( "(Amount A * Concentration A)+(Amount B * Concentration B)=(Amount final * Concentration final)
\n" ); document.write( "(1*x)+(15*0.2)=(15+x)*0.3
\n" ); document.write( "x+3=4.5+0.3x
\n" ); document.write( "x-0.3x=4.5
\n" ); document.write( "0.7x=4.5
\n" ); document.write( "0.7x/0.7=4.5/0.7
\n" ); document.write( "x=6.428
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\n" ); document.write( "6.428 liters of pure alcohol must be added to 15 liters of 20% solution to obtain a mixture which is 30 % alcohol.
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