document.write( "Question 697417: Please help me solve this word problem:\r
\n" ); document.write( "\n" ); document.write( "A big barrel contains 300 mL of a 6% solution. How much water should be added to obtain a 5% solution?\r
\n" ); document.write( "\n" ); document.write( "I have tried to make a table with each solution but I have no idea what to do after that! \n" ); document.write( "
Algebra.Com's Answer #429987 by Edwin McCravy(20060)\"\" \"About 
You can put this solution on YOUR website!
Please help me solve this word problem:\r
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document.write( "Suppose the answer is X.  That is, if we add X mL of water it \r\n" );
document.write( "will become a 5% solution\r\n" );
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document.write( "300 mL of a 6% solution, means that the barrel at the start \r\n" );
document.write( "contains 6% alcohol. Now how many mL is that?\r\n" );
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document.write( "6% of the 300 mL of liquid is .06×300 = 18 mL of alcohol.\r\n" );
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document.write( "If we add X mL of water there will be (300+X) mL of liquid\r\n" );
document.write( "But there will still be only the same 18 mL of alcohol.  So the \r\n" );
document.write( "statement we will be able to make is \r\n" );
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document.write( "\"If X is the right number of mL of water to add, then\r\n" );
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document.write( "18 mL of alcohol will equal to \r\n" );
document.write( "5% of (300+X) mL of liquid.\"  \r\n" );
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document.write( "That is,\r\n" );
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document.write( "18 = .05(300+X)\r\n" );
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document.write( "Solve that and get the answer as 60 mL of water should be added.\r\n" );
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document.write( "Checking:\r\n" );
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document.write( "If we add 60 mL of water to the 300 mL of liquid, we will then \r\n" );
document.write( "have 360 mL of liquid.\r\n" );
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document.write( "So the 18 mL of alcohol should be 5% of the 360 mL of liquid,\r\n" );
document.write( "if we are right.\r\n" );
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document.write( "So we ask \"If we take 5% of 360, will we get 18 mL?\"\r\n" );
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document.write( "So we multiply .05 times 360, and get 18 mL, so we are right.\r\n" );
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document.write( "Edwin
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