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 27 seconds. What is the length of each train (in meters)? Choose the correct choice from the following answers
A) 50.5  B) 88.5  C) 37.5  D) 55.5  E) 23.5

Rationale: "the relative speed = 46 - 36 = 10 km / hr = 10 * 5 / 18 = 25 / 9 m / s in 27 seconds , the relative difference in distance traveled is 27 * 25 / 9 = 75 meters this distance is twice the length of each train . the length of each train is 75 / 2 = 37.5 meters the answer is c ."
Answer: C