Question

Two trains starting at the same time, having lengths 200 m each are moving in same direction. If the speed of each train is 30 km/h and 35 km/h respectively, find when they will cross each other. ​

Answer 1

Let the duration be x

Let Train A be the train that traveled at 30km/h

And Train B be the train that traveled 35 km/h

Express the distance traveled by train A in term of x

Distance = Speed x Time

Distance = 30x

Express the distance traveled by train B in term of x

Distance = Speed x Time

Distance = 35x

 

The length of the each train is 200 m.

Therefore, for the train to completely cross each other, Train B (the faster train) will have to be 200 ahead of train

Convert 200 m to km

200m = 0.2 km

solve x:

35x - 30x = 0.2 km

5x = 0.2

x = 0.04 h or 2.4 mins

Answer: The train will crossed each other in 2.4 mins.

Answer 2

The train will crossed each other in 2.4 mins.