Two trains 140 m and 160 m long run at the speed of 60 km/hr and 40 km/hr respectively in opposite directions on parallel tracks. The time which they take to cross each other is?
Choose the correct choice from the following choices.
A) 7
B) 8.2
C) 2
D) 10.8
E) 11.2

Rationale: "answer : option d relative speed = 60 + 40 = 100 km / hr . = 100 * 5 / 18 = 250 / 9 m / sec . distance covered in crossing each other = 140 + 160 = 300 m . required time = 300 * 9 / 250 = 54 / 5 = 10.8 sec"
Answer: D