document.write( "Question 285448: In a 10mL solution with 10% of solute (liquid) already in it, how much (mL) solute needs to be added to make the total solute content 20% in the 10mL solution? All my friends got an answer of 1.1mL. Can someone please tell me how this is calculated? Thank you. \n" ); document.write( "
Algebra.Com's Answer #206911 by stanbon(75887)\"\" \"About 
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In a 10mL solution with 10% of solute (liquid) already in it, how much (mL) solute needs to be added to make the total solute content 20% in the 10mL solution?
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\n" ); document.write( "Note: After you add the x amount of solute you have (10+x)mL of solution.
\n" ); document.write( "I assume the x amount you add is 100% active ingredient.
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\n" ); document.write( "Equation:
\n" ); document.write( "active + active = active
\n" ); document.write( "0.10*10 + x = 0.20(10+x)
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\n" ); document.write( "Multiply thru by 100 to get:
\n" ); document.write( "10*10 + 100x = 20*10 + 20x
\n" ); document.write( "80x = 10*10
\n" ); document.write( "x = 100/80
\n" ); document.write( "x = 1.25 mL
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "
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