document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=625945>Question 625945</A>: <I><SPAN STYLE=\"word-break: break-all;\"> It takes 2 people together 12 minutes to wash a car. One person by himself takes 21 minutes. How long would it take the other person to wash the car?\r<BR>\n" );
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document.write( "I know it cannot be that one can wash the car in 6 minutes but I am stuck with this question.\r<BR>\n" );
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document.write( "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 #393930 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=393930\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> It takes 2 people together 12 minutes to wash a car. <BR>\n" );
document.write( "One person by himself takes 21 minutes.<BR>\n" );
document.write( " How long would it take the other person to wash the car? <BR>\n" );
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document.write( "Time varies inversely with no. of people, (more people, less time)<BR>\n" );
document.write( "Therefore a typical shared work equation can be used.<BR>\n" );
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document.write( "Let a = time required by the other person alone<BR>\n" );
document.write( "let the completed job = 1<BR>\n" );
document.write( "Each person will do a fraction of the job, the two fractions add up to one.<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=12%2F21 ALIGN=MIDDLE  ALT=\"12%2F21\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=12%2Fa ALIGN=MIDDLE  ALT=\"12%2Fa\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 1<BR>\n" );
document.write( "multiply thru by 21a to clear the denominators, results<BR>\n" );
document.write( "12a + 21(12) = 21a<BR>\n" );
document.write( "252 = 21a - 12a<BR>\n" );
document.write( "252 = 9a<BR>\n" );
document.write( "a = 252/9<BR>\n" );
document.write( "a = 28 minutes for the 2nd person to do it<BR>\n" );
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document.write( "You can check this on a calc, enter 12/21 + 12/28  </SPAN>\n" );
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