A man sitting on a train travelling at the rate of 50 km/hr observes that it takes 9 sec for goods train travelling in the opposite direction to pass him. If the goods train is 187.5m long. Find its speed ?
A. 40 km/hr
B. 30 km/hr
C. 24 km/hr
D. 25 km/hr
Answer : C. 24 km/hr
Explanation :
Let the speed of goods train be x km/hr.
Then, (50 + x) * ( 5 / 18 ) = 187.5 / 9
⇒ x = 25 km/hr.