document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=41834>Question 41834</A>: <I><SPAN STYLE=\"word-break: break-all;\"> how many liter of 20% solution and 70% solution do you need to make 20 liter of a 35% solution. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #26994 by </B><A HREF=/tutors/aboutme.mpl?userid=psbhowmick><B>psbhowmick(878)</B></A><img src=\"/images/stars/stars-11.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=psbhowmick><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=psbhowmick><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=26994\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 20% solution and 70% solution means that the ratio of solute to solvent by volume is 20:80 i.e. 1:4 and 70:30 i.e. 7:3 respectively.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Let us suppose that 'x' litres of the 20% solution is mixed with 'y' litres of the 70% solution to produce 20 litres of 35% solution.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Then, volume of solute added from 20% solution = 0.2x litres<BR>\n" );
document.write( "and volume of solute added from 70% solution = 0.7y litres<BR>\n" );
document.write( "Thus total volume of solute in the final solution = (0.2x + 0.7y) litres.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Then, volume of solvent added from 20% solution = 0.8x litres<BR>\n" );
document.write( "and volume of solvent added from 70% solution = 0.3y litres<BR>\n" );
document.write( "Thus total volume of solvent in the final solution = (0.8x + 0.3y) litres.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Hence the ratio of solute to solvent by volume in the final solution is <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%280.2x+%2B+0.7y%29%2F%280.8x+%2B+0.3y%29 ALIGN=MIDDLE  ALT=\"%280.2x+%2B+0.7y%29%2F%280.8x+%2B+0.3y%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "As the final solution is 35% so the ratio of solute to solvent by volume in the final solution is 35:65 i.e. 7:13.<BR>\n" );
document.write( "So, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%280.2x+%2B+0.7y%29%2F%280.8x+%2B+0.3y%29=7%2F13 ALIGN=MIDDLE  ALT=\"%280.2x+%2B+0.7y%29%2F%280.8x+%2B+0.3y%29=7%2F13\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=13%280.2x+%2B+0.7y%29=7%280.8x+%2B+0.3y%29 ALIGN=MIDDLE  ALT=\"13%280.2x+%2B+0.7y%29=7%280.8x+%2B+0.3y%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2.6x+%2B+9.1y=5.6x+%2B+2.1y ALIGN=MIDDLE  ALT=\"2.6x+%2B+9.1y=5.6x+%2B+2.1y\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3x=7y ALIGN=MIDDLE  ALT=\"3x=7y\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=7y%2F3 ALIGN=MIDDLE  ALT=\"x=7y%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" > _________(1)\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Again, the volume of the final solution is 20 litres.<BR>\n" );
document.write( "So, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+%2B+y+=+20 ALIGN=MIDDLE  ALT=\"x+%2B+y+=+20\"   DISABLED_style= \"max-width:90%; height:auto;\" > ______(2)\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Substituting for x from (1) in (2) we have<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=7y%2F3+%2B+y+=+20 ALIGN=MIDDLE  ALT=\"7y%2F3+%2B+y+=+20\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10y%2F3+=20+ ALIGN=MIDDLE  ALT=\"10y%2F3+=20+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=20%2A3%2F10 ALIGN=MIDDLE  ALT=\"y=20%2A3%2F10\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "or y = 6<BR>\n" );
document.write( "So <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+7%2A6%2F3 ALIGN=MIDDLE  ALT=\"x+=+7%2A6%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 14\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Hence 14 litres of the 20% solution has to be mixed with 6 litres of the 70% solution to yield 20 litres of 35% solution. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );