document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1173323>Question 1173323</A>: <I><SPAN STYLE=\"word-break: break-all;\"> How many grams of soil supplement that cost P280 per kilogram must be mixed with 20 kg of aluminum nitrate that costs P140 per kilogram to make a fertilizer that P180 per kilogram? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #798548 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=798548\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "If a formal algebraic solution is not required, here is a quick and easy way to solve the problem with a bit of mental arithmetic.<br><BR>\n" );
document.write( "The prices per kg of the two ingredients are P140 and 280; the price per kg of the mixture is P180.<br><BR>\n" );
document.write( "180 is 40/140 = 4/14 = 2/7 of the way from 140 to 280 (look at the three numbers on a number line, if it helps).<br><BR>\n" );
document.write( "That means 2/7 of the mixture is the more expensive ingredient and 5/7 of the mixture is the less expensive.<br><BR>\n" );
document.write( "So the amount of soil supplement that must be added is (2/7)/(5/7) = 2/5 of the amount of aluminum nitrate.<br><BR>\n" );
document.write( "ANSWER: (2/5)(20) = 8kg = 8000g<br><BR>\n" );
document.write( "CHECK:<BR>\n" );
document.write( "(20)(140)+8(280) = 2800+2240 = 5040<BR>\n" );
document.write( "28(180) = 5040<br>\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );