document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=25350>Question 25350</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Larry, Mo, and Curly wish to mow 5900 square foot lawn.  Larry can mow 70 square feet per minute, Mo can mow 50 square feet per minute, and Curly can mow 40 square feet per minute.  Mo and Curly begin mowing, but Larry has problems starting his mower and begins 30 minutes later.  All three stop mowing when the lawn is finished.  How long does Larry mow? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #13589 by </B><A HREF=/tutors/aboutme.mpl?userid=josmiceli><B>josmiceli(19441)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josmiceli><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=josmiceli><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=13589\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Moe and Curly start moeing, I mean mowing, at the same time. The lawn is getting<BR>\n" );
document.write( "mowed at the sum of their rates.<BR>\n" );
document.write( "The two of them are the only ones mowing until Larry starts 30 minutes later.<BR>\n" );
document.write( "So far,  I have this equation:<BR>\n" );
document.write( "(1) ft2 of lawn mowed = (Moes rate in ft2/min)+(Curly's rate in ft2/min)*(time elapsed)<BR>\n" );
document.write( "plugging in the numbers:<BR>\n" );
document.write( "(2) ft2 of lawn mowed = (50 ft2/min + 40 ft2/min)x 30 min<BR>\n" );
document.write( "ft2 of lawn mowed = 2700 ft2<BR>\n" );
document.write( "Then 30 minutes have elapsed, Larry starts mowing. Now I need a new equation.<BR>\n" );
document.write( "(3)ft2 of lawn left to mow / (Moe's rate + Curly's rate + Larry's rate) = time<BR>\n" );
document.write( "Note that this equation is much like:<BR>\n" );
document.write( "Distance / rate = time<BR>\n" );
document.write( "Equation (1) was like:<BR>\n" );
document.write( "Distance = rate x time<BR>\n" );
document.write( "(4) ft2 of lawn left to mow / (50 ft2/min + 40 ft2/min + 70 ft2/min) = Larry's time<BR>\n" );
document.write( "Note that the time here is the time period after Moe and Curly have been<BR>\n" );
document.write( "mowing for thirty minutes and Larry started mowing at 70 ft2/min.<BR>\n" );
document.write( "(5) (5900 ft2 - 2700 ft2) / 160 ft2/min = Larry's time<BR>\n" );
document.write( "(6) 3200 ft2 / 160 ft2/min = Larry's time<BR>\n" );
document.write( "(7) 20 min = Larry's time<BR>\n" );
document.write( "So Larry mowed for 20 minutes. Moe and Curly, by the way, mowed for 30 min + 20 min = 50 min<BR>\n" );
document.write( "So, I can check:<BR>\n" );
document.write( "((50 ft2/min + 40 ft2/min)x 50 min) + ((70 ft2/min)x 20 min = size of lawn<BR>\n" );
document.write( "4500 ft2 + 1400 ft2 = 5900 ft2<BR>\n" );
document.write( "it checks\r<BR>\n" );
document.write( "\n" );
document.write( "   </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );