document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1202222>Question 1202222</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Rainbow Robots Inc. was putting on a big demomstration. Everyone came to watch the colorful robotswash the windows at the Miller building. First the big red robot washed one half of all the windows in the building. Then the smaller green robot washed one half of the windows that were left. To the cheers of everyone watching, the tiny yellow robot washed the last 10 windows. How many windows did the rainbow  robots wash altogether? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #836964 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=836964\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "The problem can easily be worked informally by working backwards, using logical reasoning.<br><BR>\n" );
document.write( "The green robot washed half of the windows that were left when it started working. That means it left half of the windows unwashed.  Those are the 10 windows that the last robot washed.  So when the green robot started washing windows, the number left to be washed was 2(10) = 20.<br><BR>\n" );
document.write( "Similarly, the red robot washed half of all the windows, so the 20 windows it left unwashed were half of the total number of windows, making the total number of windows 2(20) = 40.<br><BR>\n" );
document.write( "ANSWER: 40<br><BR>\n" );
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