document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=30924>Question 30924</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Please help me solve the following problem.  Welder A works 3 times faster than welder B.  Together they can do a job in 3 hours.  How fast can the faster welder do the job by himself?  Thank you very much for helping me to solve this problem.   </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #17672 by </B><A HREF=/tutors/aboutme.mpl?userid=mbarugel><B>mbarugel(146)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=mbarugel><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=17672\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Hello!<BR>\n" );
document.write( "The previous answer you got for this question is actually incorrect.\r<BR>\n" );
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document.write( "This kind of problems can be solved in the following way. Let's call X to the rate at which welder A does the job per hour. For example, if he could complete the job in 10 hours, then this rate would be 1/10. He completes one tenths of the job per hour. Let's call Y to the same rate for Welder B.\r<BR>\n" );
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document.write( "We know that A's rate is 3 times higher than B's:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=X+=+3Y ALIGN=MIDDLE  ALT=\"X+=+3Y\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "We also know thta if they work together, they complete the work in 3 hours. The rate at which they work together is X + Y. If they complete it in 3 hours, then the rate should be 1/3: they complete one third of the job per hour. So we have:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=X%2BY=1%2F3 ALIGN=MIDDLE  ALT=\"X%2BY=1%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Replacing the 1st equation in the last one:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3Y+%2B+Y+=+1%2F3 ALIGN=MIDDLE  ALT=\"3Y+%2B+Y+=+1%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=4Y+=+1%2F3 ALIGN=MIDDLE  ALT=\"4Y+=+1%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=Y=1%2F12 ALIGN=MIDDLE  ALT=\"Y=1%2F12\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "So Welder B by himself can complete the job in 12 hours. Since A is 3 times faster, he can complete the job by himself in 4 hours.\r<BR>\n" );
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document.write( "I hope this helps!\r<BR>\n" );
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document.write( "Get more answers at <a  rel=nofollow HREF=http://www.onlinemathanswers.com>Online Math Answers.com</a>!\r<BR>\n" );
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document.write( " </SPAN>\n" );
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