document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=171279>Question 171279</A>: <I><SPAN STYLE=\"word-break: break-all;\"> One hose can fill an empty tank in 7 hours. A second hose can fill the empty tank in 12 hours. How long will it take to fill the empty tank if both hoses are used? Write an equation and solve. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #126435 by </B><A HREF=/tutors/aboutme.mpl?userid=solver91311><B>solver91311(24713)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=solver91311><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/cgi-bin/show-face.mpl?user=solver91311><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=126435\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> One of the hoses can fill the tank in 7 hours, so that hose can fill <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F7 ALIGN=MIDDLE  ALT=\"1%2F7\"   DISABLED_style= \"max-width:90%; height:auto;\" > of the tank in one hour.  Likewise, the other hose can fill <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F12 ALIGN=MIDDLE  ALT=\"1%2F12\"   DISABLED_style= \"max-width:90%; height:auto;\" > of the tank in one hour.\r<BR>\n" );
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document.write( "Using both hoses, you can fill <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F7%2B1%2F12=12%2F84%2B7%2F84=19%2F84 ALIGN=MIDDLE  ALT=\"1%2F7%2B1%2F12=12%2F84%2B7%2F84=19%2F84\"   DISABLED_style= \"max-width:90%; height:auto;\" > of the tank in one hour.\r<BR>\n" );
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document.write( "Therefore, both hoses can fill the tank in 84/19 hours, or just under 4 and a half hours (you can go ahead and calculate the hours, minutes, and seconds if you are so inclined).\r<BR>\n" );
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document.write( "In general, for two entities performing work, if entity 1 can do the entire job in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5B1%5D ALIGN=MIDDLE  ALT=\"x%5B1%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" > hours and entity 2 can do the entire job in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5B2%5D ALIGN=MIDDLE  ALT=\"x%5B2%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" > hours, then both working together can do the job in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28x%5B1%5Dx%5B2%5D%29%2F%28x%5B1%5D%2Bx%5B2%5D%29 ALIGN=MIDDLE  ALT=\"%28x%5B1%5Dx%5B2%5D%29%2F%28x%5B1%5D%2Bx%5B2%5D%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > hours.\r<BR>\n" );
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document.write( "This is extensible to as many entities as you like simply by adding factors to the numerator and terms to the denominator.  For example, with three entities, the formula is:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28x%5B1%5Dx%5B2%5Dx%5B3%5D%29%2F%28x%5B1%5D%2Bx%5B2%5D%2Bx%5B3%5D%29 ALIGN=MIDDLE  ALT=\"%28x%5B1%5Dx%5B2%5Dx%5B3%5D%29%2F%28x%5B1%5D%2Bx%5B2%5D%2Bx%5B3%5D%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > \r<BR>\n" );
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