Two trains are moving in opposite directions with speed of 90 km/hr and 90 km/hr respectively. Their lengths are 1.10 km and 0.9 km respectively. the slower train cross the faster train in --- seconds Choose the correct choice from the following.
A) 56  B) 40  C) 47  D) 26  E) 25

Rationale: "explanation : relative speed = 90 + 90 = 180 km / hr ( since both trains are moving in opposite directions ) total distance = 1.1 + . 9 = 2 km time = 2 / 180 hr = 1 / 90 hr = 3600 / 90 seconds = 40 seconds answer : option b"
Answer: B