Two trains are running in opposite direction with the same speed. If the length of each train is 320 metres and they cross each other in 18 seconds then what is the speed of each train?

Correct option is B

Given:
Length of each train = 320 meters, Time = 18 seconds
Formula Used:
Relative Speed = Total Distance / Time
Solution:
Let the speed of each train be x m/sec
Then relative speed of the two trains = 2x m/sec
Total distance covered = 320 + 320 = 640m
Total time = 18sec
So 2x = 640/18
x = $$\frac{320}{18} \ m/sec$$ 

in km/h 

= $$\frac{320}{18}\times \frac{18}5$$ = 64 km/hr.
∴ Speed of each train = 64 km/hr.