document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1180854>Question 1180854</A>: <I><SPAN STYLE=\"word-break: break-all;\"> You need a 95% alcohol solution. On hand, you have a 15 mL of a 10% alcohol mixture. How much pure alcohol will you need to add to obtain the desired solution?\r<BR>\n" );
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document.write( "You will need<BR>\n" );
document.write( " (?) mL of pure alcohol<BR>\n" );
document.write( "to obtain<BR>\n" );
document.write( "(?) mL of the desired 95% solution. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #810646 by </B><A HREF=/tutors/aboutme.mpl?userid=math_tutor2020><B>math_tutor2020(3817)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=math_tutor2020><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=810646\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <font color=black size=3><BR>\n" );
document.write( "The question is <BR>\n" );
document.write( "\"How much pure alcohol will you need to add to obtain the desired solution?\"<BR>\n" );
document.write( "So we'll make that x and the goal of course is to find x.\r<BR>\n" );
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document.write( "x = amount of pure alcohol to add to the existing mix\r<BR>\n" );
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document.write( "The existing solution is 15 mL of 10% alcohol<BR>\n" );
document.write( "Meaning, 15*0.10 = 1.5 mL of pure alcohol is present in this bottle. \r<BR>\n" );
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document.write( "So x+1.5 mL of pure alcohol is the total after adding those x mL of pure alcohol. \r<BR>\n" );
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document.write( "The total amount of solution is x+15 mL (which consists of pure alcohol plus water).\r<BR>\n" );
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document.write( "The ratio<BR>\n" );
document.write( "(x+1.5)/(x+15)<BR>\n" );
document.write( "represents the percentage of alcohol after we add in that x mL of pure alcohol.\r<BR>\n" );
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document.write( "Set this ratio equal to 0.95 and solve for x<BR>\n" );
document.write( "(x+1.5)/(x+15) = 0.95<BR>\n" );
document.write( "x+1.5 = 0.95(x+15)<BR>\n" );
document.write( "x+1.5 = 0.95x+14.25<BR>\n" );
document.write( "x-0.95x  = 14.25-1.5<BR>\n" );
document.write( "0.05x  = 12.75<BR>\n" );
document.write( "x = 12.75/0.05<BR>\n" );
document.write( "x = 255\r<BR>\n" );
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document.write( "If we add 255 mL of pure alcohol to the original 1.5 mL of pure alcohol, then we have 255+1.5 = 256.5 mL of pure alcohol. <BR>\n" );
document.write( "The total amount of solution is x+15 = 255+15 = 270 mL\r<BR>\n" );
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document.write( "Note how<BR>\n" );
document.write( "256.5/270 = 0.95 = 95%<BR>\n" );
document.write( "showing we have a 95% alcohol mix now.\r<BR>\n" );
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document.write( "Answers: <BR>\n" );
document.write( "You'll need to add <u>255 mL</u> of pure alcohol<BR>\n" );
document.write( "This will lead to <u>270 mL</u> of 95% solution<BR>\n" );
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document.write( " </SPAN>\n" );
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