document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=112211>Question 112211</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a train leaves a station and travels east at 72km/h. three hours later a second train leaves on a parallel track and travels at 120km/h. When will the second train overtake the first train?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #81993 by </B><A HREF=/tutors/aboutme.mpl?userid=ptaylor><B>ptaylor(2198)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ptaylor><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=ptaylor><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=81993\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <BR>\n" );
document.write( "Distance(d)=Rate(r) times Time(t) or d=rt; t=d/r and r=d/t\r<BR>\n" );
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document.write( "Let t=number of hours that elapses after the second train leaves until the first train is overtaken\r<BR>\n" );
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document.write( "When the second train leaves, the first train has already <BR>\n" );
document.write( "travelled 72*3 or 216 mi\r<BR>\n" );
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document.write( "Now we know that when the two trains have travelled the same distance, the second train will have overtaken the first.\r<BR>\n" );
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document.write( "distance first train travels=216+72t<BR>\n" );
document.write( "distance 2nd train travels=120t\r<BR>\n" );
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document.write( "So. our equation to solve is:\r<BR>\n" );
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document.write( "216+72t=120t  subtract 72t from both sides\r<BR>\n" );
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document.write( "216+72t-72t=120t-72t  collect like terms\r<BR>\n" );
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document.write( "216=48t  divide both sides by 48\r<BR>\n" );
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document.write( "t=4.5 hours-----------------------time it takes 2nd train to overtake the first train after the 2nd train leaves.\r<BR>\n" );
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document.write( "CK\r<BR>\n" );
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document.write( "216+72*4.5=120*4.5<BR>\n" );
document.write( "540=540\r<BR>\n" );
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document.write( "Hope this helps---ptaylor<BR>\n" );
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