document.write( "Question 220179: A Chemist has a solution that is 5% alcohol and one that is 20% alcohol. How many liters of each should be mixed together to make 100 liters of 15% solition? \n" ); document.write( "

Algebra.Com's Answer #165403 by ptaylor(2198) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let x=amount of 5% solution needed
\n" ); document.write( "Then 100-x=amount of 20% solution needed
\n" ); document.write( "Now we know that the amount of pure alcohol in the 5% solution (0.05x) plus the amount of pure alcohol in the 20% solution (0.20(100-x)) has to equal the amount of pure alcohol in the final mixture(0.15*100), so our equation to solve is:\r
\n" ); document.write( "\n" ); document.write( "0.05x+0.20(100-x)=0.15*100 get rid of parens
\n" ); document.write( "0.05x+20-0.20x=15 subtract 20 from each side
\n" ); document.write( "0.05x+20-20-0.20x=15-20 collect like terms
\n" ); document.write( "-0.15x=-5 divide each side by -0.15
\n" ); document.write( "x=33 1/3 liters----amount of 5% solution needed
\n" ); document.write( "100-x=100-33 1/3=66 2/3 liters amount of 20% solution needed
\n" ); document.write( "CK
\n" ); document.write( "(33 1/3)*(5/100)+(20/100)(66 2/3)=0.15*100
\n" ); document.write( "(100/3)(5/100)+(20/100)(200/3)=15
\n" ); document.write( "5/3 +40/3=15
\n" ); document.write( "45/3=15
\n" ); document.write( "15=15\r
\n" ); document.write( "\n" ); document.write( "Hope this helps---ptaylor \n" ); document.write( "

\n" );