document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=35083>Question 35083</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0131411160/algebrahomeworkh></A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> I don't get this. Shouldn't she just make the mixture using the 60% solution?<BR>\n" );
document.write( "Here's the problem: Susan Staples, a pharmacist, has a 60% solution of the drug sodium iodite. She also has a 25% solution of the same drug. She gets a prescription calling for a 40% solution of the drug. How much of each solution should she mix to make 0.5 liter of the 40% solution? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #21290 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=21290\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Here's the problem: Susan Staples, a pharmacist, has a 60% solution of the drug sodium iodite. She also has a 25% solution of the same drug. She gets a prescription calling for a 40% solution of the drug. How much of each solutionshould she mix to make 0.5 liter of the 40% solution?\r<BR>\n" );
document.write( "\n" );
document.write( "Let amount of 60% solution be \"x\" liters <BR>\n" );
document.write( "Then amount of 25% solution must be \"0.5-x\" liters<BR>\n" );
document.write( "Amount of sodium iodite in the 60% batch is 0.60x liters<BR>\n" );
document.write( "Amount of sodium iodite in the 25% batch is 0.25(0.5-x)=0.125-0.25x liters<BR>\n" );
document.write( "EQUATION:<BR>\n" );
document.write( " sodium iodite + sodium iodite = 0.40(0.5 liters)<BR>\n" );
document.write( " 0.60x + 0.125-0.25x = 0.20 liters<BR>\n" );
document.write( " Multiply thru by 1000 to get:<BR>\n" );
document.write( "600x +125 - 250x = 200<BR>\n" );
document.write( "350x=75<BR>\n" );
document.write( "x=0.214 liters (amount of 60% solution)<BR>\n" );
document.write( "0.5-x= 0.5-0.214= 0.286 liters  (amount of 25% solution)<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );