document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=142242>Question 142242</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Joe cleans his room in 7 hours.  With his mom, it takes them 3 hours.  How long does it take mom alone? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #103579 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=103579\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Joe cleans his room in 7 hours. With his mom, it takes them 3 hours. How long does it take mom alone?<BR>\n" );
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document.write( "Joe's rate = 1/7 job/hr<BR>\n" );
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document.write( "Joe and Mom together's rate = 1/3 job/hr.<BR>\n" );
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document.write( "Mom's rate alone is 1/x job/hr<BR>\n" );
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document.write( "EQUATION:<BR>\n" );
document.write( "rate + rate = together rate<BR>\n" );
document.write( "1/7 + 1/x = 1/3<BR>\n" );
document.write( "Multiply thru by 21x to get:<BR>\n" );
document.write( "3x + 21 = 7x<BR>\n" );
document.write( "4x = 21<BR>\n" );
document.write( "x = 21/4 = 5 1/4 hr (time it will take Mom alone)<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( " </SPAN>\n" );
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