Two trains 200 m and 800 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?
Choices
A) 10.6	B) 10.9	C) 36	D) 10.8	E) 10.1

Rationale: "relative speed = 60 + 40 = 100 km / hr . = 100 * 5 / 18 = 250 / 9 m / sec . distance covered in crossing each other = 200 + 800 = 1000 m . required time = 1000 * 9 / 250 = 36 sec . answer : c"
Answer: C