document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=972254>Question 972254</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Three trains start at different times on a 100 mile journey.Train A leaves late and stops at a station for 5 minutes.its average speed is 40mph.Train B leaves 20 minutes late and  stops at a station for 14 minutes. its average speed is 50mph. Train c leaves 30 minutes late and  stops at a station for 10 minutes.its average speed is 50mph.which train completes the journey in the shortest time </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #594596 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=594596\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> there may be a few ways to calculate this.\r<BR>\n" );
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document.write( "let's try this one.\r<BR>\n" );
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document.write( "train B.\r<BR>\n" );
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document.write( "when it is moving, train B travels at 50 mph.<BR>\n" );
document.write( "100 miles divided by 50 miles per hour is 2 hours.<BR>\n" );
document.write( "train B left 20 minutes late and stopped at a station for 14 minutes.<BR>\n" );
document.write( "20 + 14 = 34 minutes divided by 60 minutes per hour = 34/60 hours <BR>\n" );
document.write( "take 2 hours and add 34/60 hours and you get 2 hours and 34/60 hours total time for train B to travel 100 miles.<BR>\n" );
document.write( "this is equivalent to 2.57 hours.\r<BR>\n" );
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document.write( "train C.\r<BR>\n" );
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document.write( "when it is moving, train C travels at 50 mph.<BR>\n" );
document.write( "100 miles divided by 50 miles per hour is 2 hours.<BR>\n" );
document.write( "train C left 30 minutes late and stops at a station for 10 minutes.<BR>\n" );
document.write( "30 + 10 = 40 minutes divided by 60 minutes per hour = 40/60 hours.<BR>\n" );
document.write( "take 2 hours and add 40/60 hours and you get 2 hours and 40/60 hours total time for train C to travel 100 miles.<BR>\n" );
document.write( "this is equivalent to 2.67 hours.\r<BR>\n" );
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document.write( "so far train B took less time overall.\r<BR>\n" );
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document.write( "train A.\r<BR>\n" );
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document.write( "train A leaves late, but you haven't said how late.<BR>\n" );
document.write( "that's a missing point of information for train A.<BR>\n" );
document.write( "it stops at a station for 5 minutes.<BR>\n" );
document.write( "it's average speed is 40 mph, when it is moving!!!!!<BR>\n" );
document.write( "this is a key assumption.<BR>\n" );
document.write( "average speed when it is moving is different than average speed overall.<BR>\n" );
document.write( "average speed overall includes the time it is not moving.<BR>\n" );
document.write( "the train that takes the longest time will have the lowest overall speed regardless of what speed it is traveling at when it is moving.\r<BR>\n" );
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document.write( "train A would take 100/40 = 2.5 hours without any stops and without being late.<BR>\n" );
document.write( "train A stopped at a station for 5 minutes, so the total time it takes without being late is 2.5 + 5/60 hours.<BR>\n" );
document.write( "this is equivalent to 2.58 hours.<BR>\n" );
document.write( "you still need to add x hours to this for the number of hours that train A is late.<BR>\n" );
document.write( "it doesn't matter.<BR>\n" );
document.write( "even if train A left on time, it would not have the fastest time overall.\r<BR>\n" );
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document.write( "based on this analysis, train B takes the shortest time at 2.57 hours.<BR>\n" );
document.write( "train A, even if it was not late starting, took 2.58 hours.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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