document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1165719>Question 1165719</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A chemist has 50 g of a solution that is 10% acid if he wants to increase the strength to 20% how much pure acid should he add?<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #790220 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13200)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=greenestamps><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/cgi-bin/show-face.mpl?user=greenestamps><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=790220\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "(1) A typical setup using formal algebra....<br><BR>\n" );
document.write( "50g of 10% acid, plus x g of 100% acid, equals (50+x) g of 20% acid:<br><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=.10%2850%29%2B1.00%28x%29+=+.20%2850%2Bx%29 ALIGN=MIDDLE  ALT=\".10%2850%29%2B1.00%28x%29+=+.20%2850%2Bx%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><br><BR>\n" );
document.write( "Solve using basic algebra.<br><BR>\n" );
document.write( "(2) A quick and easy way to solve ANY 2-part mixture problem like this....<br><BR>\n" );
document.write( "Look at the three percentages 10, 20, and 100 on a number line and see where the 20% is in relation to the 10% and 100%.<br><BR>\n" );
document.write( "The 20% is 1/9 of the way from 10% to 100%.  (From 10 to 100 is a difference of 90; from 10 to 20 is a difference of 10; 10/90 = 1/9.)<br><BR>\n" );
document.write( "That means 1/9 of the mixture must be the added 100% acid.<br><BR>\n" );
document.write( "So the 50g of 10% acid is 8/9 of the mixture; 1/9 of the mixture is then 1/8 of 50g, or 6.25g.<br><BR>\n" );
document.write( "ANSWER: 6.25 grams of 100% acid.<br><BR>\n" );
document.write( "CHECK:<BR>\n" );
document.write( ".10(50)+1.00(6.25) = 5+6.25 = 11.25<BR>\n" );
document.write( ".20(50+6.25) = .20(56.25) = 11.25<br><BR>\n" );
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