document.write( "Question 1158396: how many mL of 50% dextrose solution and how many mL of water are needed to prepare 100 mL of 15 % dextrose solution? \n" ); document.write( "

Algebra.Com's Answer #781325 by greenestamps(13200) $\"\"$ $\"About$

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\n" ); document.write( "(1) A standard algebraic solution....

\n" ); document.write( "x mL of the 50% dextrose, plus (100-x) mL of water (0% dextrose), equals 15% of 100 mL:

\n" ); document.write( " $\".50%28x%29%2B0%28100-x%29+=+.15%28100%29\"$
\n" ); document.write( " $\".5x+=+15\"$
\n" ); document.write( " $\"x+=+15%2F.5+=+30\"$
\n" ); document.write( "ANSWER: 30 mL of 50%; 70 mL of water

\n" ); document.write( "(2) Basically the same solution, informally....

\n" ); document.write( "The water is 0% dextrose, so all of the dextrose comes from the 50% dextrose solution.
\n" ); document.write( "In the final mixture, the amount of dextrose is 15% of 100 mL, or 15 mL.
\n" ); document.write( "The 50% dextrose solution is one-half dextrose; to get 15mL of dextrose, you need 30 mL of solution.

\n" ); document.write( "(3) A completely different method of solving....

\n" ); document.write( "You are mixing 0% and 50% dextrose to get 15% dextrose.
\n" ); document.write( "15% is 15/50 = 3/10 of the way from 0% to 50%.
\n" ); document.write( "So 3/10 of the mixture is the 50% dextrose.
\n" ); document.write( "3/10 of 100 mL is 30 mL.

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