Two trains crossing on parallel rails moving in the same direction

[neha1]

1. two trains 200 meteres and 150 meters are running on the parallel rails at this rate of 40 km/hr and 45 km/hr.in how much time will they cross each other if they are running on the same direction

Homework Equations

3. speed=distance/time
train1 =200*40*5/18
train2=150*45*5/18

 

[Chi Meson]

All that matters are their relative displacement and their relative speed.

How far apart are they, initially?

What is the difference in their speeds?