document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=56227>Question 56227</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Problem:\r<BR>\n" );
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document.write( "a person can wash their car in 30 minutes.  A friend can do it in 20 minutes.  How long will it take them if they work together.  \r<BR>\n" );
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document.write( "I really have a tough time with word problems.  thank you! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #38148 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=38148\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> a person can wash their car in 30 minutes. A friend can do it in 20 minutes. How long will it take them if they work together. <BR>\n" );
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document.write( "You have to understand the difference between time and rate.<BR>\n" );
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document.write( "Amount of time for 1st person = 30 min./job ; rate = (1/30) job/min<BR>\n" );
document.write( "That means every minute the person does 1/30th of the job.<BR>\n" );
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document.write( "Amount of time for the friend= 20 min/job ; rate = (1/20)job/min.<BR>\n" );
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document.write( "Amount of time to do job together = x min/job  ; rate =(1/x) job/min<BR>\n" );
document.write( "EQUATION:<BR>\n" );
document.write( "rate of 1st + rate of friend = rate together<BR>\n" );
document.write( "1/30 + 1/20 = 1/x<BR>\n" );
document.write( "Multiply thru by 60x to get:<BR>\n" );
document.write( "2x + 3x =60<BR>\n" );
document.write( "5x=60<BR>\n" );
document.write( "x=12 minutes (this is the time they will take working together)<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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