document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1173103>Question 1173103</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A farmer looked out his window and saw a total of 21 cows and ducks. He was bored so he counted all the legs of the cows and ducks. He counted a total of 72 legs. How many of the 21 animals were ducks? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #798266 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=798266\">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, this kind of problem can be solved using logical reasoning and simple mental arithmetic.<br><BR>\n" );
document.write( "(1) all 21 animals being ducks would mean 2(21) = 42 legs; that is 72-42=30 less than the actual number.<BR>\n" );
document.write( "(2) Each cow has 2 more legs than each duck.<BR>\n" );
document.write( "(3) The number of cows needed to make those additional 30 legs is 30/2 = 15.<BR>\n" );
document.write( "(4) 15 cows means 21-15 = 6 ducks.<br><BR>\n" );
document.write( "ANSWER: 6 ducks<br><BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );