document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=152882>Question 152882</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A man can construct a wall in 20 hrs.  With the help of his apprentice assistant the task would take 12 hrs.  How long would it take the apprentice, working alone, to construct the wall?\r<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #112349 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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=112349\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let x=# of hours apprentice can complete the job\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=W=RT ALIGN=MIDDLE  ALT=\"W=RT\"   DISABLED_style= \"max-width:90%; height:auto;\" > Start with the work done formula.\r<BR>\n" );
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document.write( "Since the \"man can construct a wall in 20 hrs\", this means that T=20 \r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1=R%2820%29 ALIGN=MIDDLE  ALT=\"1=R%2820%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > Plug in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=W=1 ALIGN=MIDDLE  ALT=\"W=1\"   DISABLED_style= \"max-width:90%; height:auto;\" > (for 1 job) and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=T=20 ALIGN=MIDDLE  ALT=\"T=20\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F20=R ALIGN=MIDDLE  ALT=\"1%2F20=R\"   DISABLED_style= \"max-width:90%; height:auto;\" > Divide both sides by 20.\r<BR>\n" );
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document.write( "So the man's rate is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F20 ALIGN=MIDDLE  ALT=\"1%2F20\"   DISABLED_style= \"max-width:90%; height:auto;\" > of a wall per hour\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=W=RT ALIGN=MIDDLE  ALT=\"W=RT\"   DISABLED_style= \"max-width:90%; height:auto;\" > Go back to the first formula\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1=Rx ALIGN=MIDDLE  ALT=\"1=Rx\"   DISABLED_style= \"max-width:90%; height:auto;\" > Plug in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=W=1 ALIGN=MIDDLE  ALT=\"W=1\"   DISABLED_style= \"max-width:90%; height:auto;\" > and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=T=x ALIGN=MIDDLE  ALT=\"T=x\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2Fx=R ALIGN=MIDDLE  ALT=\"1%2Fx=R\"   DISABLED_style= \"max-width:90%; height:auto;\" > Divide both sides by x.\r<BR>\n" );
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document.write( "So the apprentice's rate is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2Fx ALIGN=MIDDLE  ALT=\"1%2Fx\"   DISABLED_style= \"max-width:90%; height:auto;\" > of a wall per hour\r<BR>\n" );
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document.write( "Now add the two rates to get <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=R=1%2F20%2B1%2Fx=x%2F%2820x%29%2B20%2F%2820x%29=%28x%2B20%29%2F%2820x%29 ALIGN=MIDDLE  ALT=\"R=1%2F20%2B1%2Fx=x%2F%2820x%29%2B20%2F%2820x%29=%28x%2B20%29%2F%2820x%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "So together, their rate is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=R=%28x%2B20%29%2F%2820x%29 ALIGN=MIDDLE  ALT=\"R=%28x%2B20%29%2F%2820x%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=W=RT ALIGN=MIDDLE  ALT=\"W=RT\"   DISABLED_style= \"max-width:90%; height:auto;\" > Go back to the first formula\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1=%28%28x%2B20%29%2F%2820x%29%29%2812%29 ALIGN=MIDDLE  ALT=\"1=%28%28x%2B20%29%2F%2820x%29%29%2812%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > Plug in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=W=1 ALIGN=MIDDLE  ALT=\"W=1\"   DISABLED_style= \"max-width:90%; height:auto;\" >, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=R=%28x%2B20%29%2F%2820x%29 ALIGN=MIDDLE  ALT=\"R=%28x%2B20%29%2F%2820x%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=T=12 ALIGN=MIDDLE  ALT=\"T=12\"   DISABLED_style= \"max-width:90%; height:auto;\" > (this is the time for them if they work together)\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=20x=12%28x%2B20%29 ALIGN=MIDDLE  ALT=\"20x=12%28x%2B20%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > Multiply both sides by <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=20x ALIGN=MIDDLE  ALT=\"20x\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=20x=12x%2B240 ALIGN=MIDDLE  ALT=\"20x=12x%2B240\"   DISABLED_style= \"max-width:90%; height:auto;\" > Distribute\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=20x-12x=240 ALIGN=MIDDLE  ALT=\"20x-12x=240\"   DISABLED_style= \"max-width:90%; height:auto;\" > Subtract <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=12x ALIGN=MIDDLE  ALT=\"12x\"   DISABLED_style= \"max-width:90%; height:auto;\" > from both sides.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=8x=240 ALIGN=MIDDLE  ALT=\"8x=240\"   DISABLED_style= \"max-width:90%; height:auto;\" > Combine like terms on the left side.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=%28240%29%2F%288%29 ALIGN=MIDDLE  ALT=\"x=%28240%29%2F%288%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > Divide both sides by <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=8 ALIGN=MIDDLE  ALT=\"8\"   DISABLED_style= \"max-width:90%; height:auto;\" > to isolate <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x ALIGN=MIDDLE  ALT=\"x\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=30 ALIGN=MIDDLE  ALT=\"x=30\"   DISABLED_style= \"max-width:90%; height:auto;\" > Reduce.\r<BR>\n" );
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document.write( "Answer:\r<BR>\n" );
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document.write( "So the answer is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=30 ALIGN=MIDDLE  ALT=\"x=30\"   DISABLED_style= \"max-width:90%; height:auto;\" > which means that it'll take 30 hours for the apprentice to do it alone.\r<BR>\n" );
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