document.write( "Question 775842: It takes 12 seconds for two trains to pass one another when moving in opposite directions. If they are in the same direction, it will take the faster train 3 minutes to pass the slower one. If the trains are 130 meters and 120 meters long, respectively, what are the rates of the two trains? \n" ); document.write( "
Algebra.Com's Answer #473203 by mananth(16946)\"\" \"About 
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It takes 12 seconds for two trains to pass one another when moving in opposite directions. If they are in the same direction, it will take the faster train 3 minutes to pass the slower one. If the trains are 130 meters and 120 meters long, respectively, what are the rates of the two trains?\r
\n" ); document.write( "\n" ); document.write( "train I speed = x
\n" ); document.write( "train II speed =y\r
\n" ); document.write( "\n" ); document.write( "When they are in opposite direction the effective speed = x+y\r
\n" ); document.write( "\n" ); document.write( "Time taken = 12 seconds = 12/3600 hrs. = 1/300 hours\r
\n" ); document.write( "\n" ); document.write( "The total length of trains is the distance d=250 m = 0.25 km\r
\n" ); document.write( "\n" ); document.write( "Distance = speed * time\r
\n" ); document.write( "\n" ); document.write( "(x+y)*1/300 =0. 250\r
\n" ); document.write( "\n" ); document.write( "When in same direction\r
\n" ); document.write( "\n" ); document.write( "effective speed = x-y
\n" ); document.write( "time = 3 minutes = 3/60 = 1/20 hours\r
\n" ); document.write( "\n" ); document.write( "(x-y)*1/20 = 0.250\r
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\n" ); document.write( "\n" ); document.write( "(x+y)*1/300 = 0.250\r
\n" ); document.write( "\n" ); document.write( "x+y = 75
\n" ); document.write( "x-y= 5\r
\n" ); document.write( "\n" ); document.write( "Add the two equations\r
\n" ); document.write( "\n" ); document.write( "2x=80\r
\n" ); document.write( "\n" ); document.write( "/2
\n" ); document.write( "x=40 => speed of Train I\r
\n" ); document.write( "\n" ); document.write( "x+y=75\r
\n" ); document.write( "\n" ); document.write( "so speed of Train II = 75-40=35 kph\r
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