Two trains of equal length are running on parallel lines in the same direction at 46 km/hr and 36 km/hr. The faster train passes the slower train in 36 seconds. The length of each train is ?  Choose the most appropriate option:
A) 40 meter  B) 45 meter  C) 50 meter  D) 55 meter  E) none of these

Rationale: "explanation : let the length of each train is x meter distance will be x + x = 2 x relative speed = 46 - 36 = 10 km / hr = 10 * ( 5 / 18 ) = 25 / 9 m / sec distance = speed * time 2 x = 25 / 9 ∗ 36 2 x = 100 = > x = 50 so length of both the trains are 50 meters option c"
Answer: C