document.write( "Question 346023: 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 #247555 by ankor@dixie-net.com(22740)\"\" \"About 
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It takes 12 seconds for two trains to pass one another when moving in opposite directions.
\n" ); document.write( " If they are in the same direction, it will take the faster train 3 minutes to pass the slower one.
\n" ); document.write( " If the trains are 130 meters and 120 meters long, respectively, what are the rates of the two trains?
\n" ); document.write( ":
\n" ); document.write( "Let a = speed of the faster train
\n" ); document.write( "let b = speed of the slower
\n" ); document.write( ":
\n" ); document.write( "Trains meeting each other
\n" ); document.write( "The sum of the speed of the two trains (in meters/sec)
\n" ); document.write( "speed = dist/time
\n" ); document.write( "a + b = \"%28%28130%2B120%29%29%2F12\"
\n" ); document.write( "a + b = 20.83 m/sec is the sum of their speeds
\n" ); document.write( ":
\n" ); document.write( "Trains going in the same direction (change 3 min to 180 sec
\n" ); document.write( "a - b = \"%28%28130%2B120%29%29%2F180\"
\n" ); document.write( "a - b = 1.39 m/sec is the difference of their speed
\n" ); document.write( ":
\n" ); document.write( "Use elimination
\n" ); document.write( "a + b = 20.83
\n" ); document.write( "a - b = 1.39
\n" ); document.write( "----------------adding eliminates b, find a
\n" ); document.write( "2a = 22.22
\n" ); document.write( "a = \"22.22%2F2\"
\n" ); document.write( "a = 11.11 m/sec is the speed of train a
\n" ); document.write( "In km/hr: \"%28%2811.11%2A3600%29%29%2F1000\" ~ 40 km/hr
\n" ); document.write( ":
\n" ); document.write( "then using the sum equation find b
\n" ); document.write( "11.11 + b = 20.83
\n" ); document.write( "b = 20.83 - 11.11
\n" ); document.write( "b = 9.72 m/sec is the speed of train b
\n" ); document.write( "In km/hr \"%28%289.72%2A3600%29%29%2F1000\" ~ 35 km/hr\r
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