Question

57. A train 'B' speeding with 120 km/hr crosses another train '
running in
the same direction in 2 minutes. If the lengths of trains 'B' and 'C' are 100
meters and 200 meters respectively, what is the speed of train 'C?​

Answer 1

Speed of train B relative to C = (120 - x) kmph

= [(120−x)×518] m/sec

= (600−5x18) m/sec

Distance covered = 100 + 200 = 300 m

∴300(600−5x18) = 120

=> 300 = 120(600−5x)18

=> 10 × 9 = 2 ( 600 - 5x )

=> 90 = 1200 - 10x

=> 10x = 1200 - 90

=> x = 111010 = 111

Hence, the speed of train is 111 kmph.