They will cross each other after 0.455hr=27.32min=1639.30sec

Answer:

Relative speed = (120+80)

km/hr=200km/hr = 200× 5/18m /sec=100× 5/9m/sec = 500/9m/sec

Let the length of the train be x metres.

SPEED = DISTANCE/TIME

500/9= x+270/9

500 = x+270

x = 500 - 270 = 230m

x + 2709 = 5009