document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=280398>Question 280398</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Jack usually mows his lawn in 3 hours. Jill can mow the same yard in 4 hours. How much time would it take for them to mow the yard together? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #203787 by </B><A HREF=/tutors/aboutme.mpl?userid=dabanfield><B>dabanfield(803)</B></A><img src=\"/images/stars/stars-11.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=dabanfield><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=203787\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Jack usually mows his lawn in 3 hours. Jill can mow the same yard in 4 hours. How much time would it take for them to mow the yard together?\r<BR>\n" );
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document.write( "The amount of lawn mowed is the product of the rate of mowing and the elapsed time (i.e. m = r*t).\r<BR>\n" );
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document.write( "Jack's rate of mowing is 1/3. Jill's ratre is 1/4.  So their combines rate of mowing is 1/3 + 1/4. Let t be the ime needed. Then we have for mowing 1 lawn:\r<BR>\n" );
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document.write( "1 = (1/3 + 1/4)*t <BR>\n" );
document.write( "1 = (4/12 + 3/12)*t<BR>\n" );
document.write( "1 = (7/12)*t<BR>\n" );
document.write( "t = 1/(7/12) <BR>\n" );
document.write( "t = 1*(12/7)<BR>\n" );
document.write( "t = 12/7 hours </SPAN>\n" );
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