document.write( "Question 214670: Trains a and b are traveling in the same direction on parallel tracks. Train A is traveling at 80mph...? B is at 88mpr. Train A passes a station at 8:20pm. If train B passes the same station at 8:50pm; at what time will train B catch up to train A? \n" ); document.write( "
Algebra.Com's Answer #162111 by Edwin McCravy(20056)\"\" \"About 
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Edwin's solution:\r
\n" ); document.write( "\n" ); document.write( "Trains a and b are traveling in the same direction on parallel tracks. Train A is traveling at 80mph...? B is at 88mpr. Train A passes a station at 8:20pm. If train B passes the same station at 8:50pm; at what time will train B catch up to train
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document.write( "You can do it in your head:\r\n" );
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document.write( "When train B passes the station at 8:50pm, train\r\n" );
document.write( "A has been travelingfor half an hour at 80mph \r\n" );
document.write( "(since 8:20pm) and so it is 40 miles from train B.\r\n" );
document.write( "So A's approach rate is 88-80 or 8mph and so it \r\n" );
document.write( "will take 5 hours to shrink A's 40 mile head start \r\n" );
document.write( "down to zero. So 5 hours from 8:50pm is 1:50am.\r\n" );
document.write( "(That is, provided the train did not cross over \r\n" );
document.write( "a time zone!)  \r\n" );
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document.write( "  \r\n" );
document.write( "But your teacher doesn't want you to do it that way.  That's too easy\r\n" );
document.write( "and you don't learn any algebra:\r\n" );
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document.write( "Let t = the time train B travels till it catches A.\r\n" );
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document.write( "Make this chart:\r\n" );
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document.write( "Train    Distance   Rate   Time\r\n" );
document.write( "  A \r\n" );
document.write( "  B\r\n" );
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document.write( "Then fill in \"t%2B.5\" for the time of train A,\r\n" );
document.write( "since it traveled for half an hour (or .5 hours)\r\n" );
document.write( "past the station when B left the station.\r\n" );
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document.write( "Also fill in their rates of 80mph and 88mph\r\n" );
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document.write( "Train    Distance   Rate   Time\r\n" );
document.write( "  A                  80    t+.5  \r\n" );
document.write( "  B                  88     t\r\n" );
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document.write( "Now we use  Distance = Rate x Time to fill in\r\n" );
document.write( "the distances both will have traveled from the station.\r\n" );
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document.write( "Train    Distance   Rate   Time\r\n" );
document.write( "  A       80(t+.5)   80    t+.5  \r\n" );
document.write( "  B         88t      88     t\r\n" );
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document.write( "When B catches up to A they will have traveled the\r\n" );
document.write( "same distance so we set those two distances equal:\r\n" );
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document.write( "A's distance from station = B's distance from station  \r\n" );
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document.write( "             90(t+.5) = 88t\r\n" );
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document.write( "Solve that and get t=5 hours\r\n" );
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document.write( "Then 5 hourslater than 8:50pm is 1:50am, provided no \r\n" );
document.write( "time zone was crossed.\r\n" );
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document.write( "Edwin
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