Question :A bird fly 200km/hr.Two trains coming oppositely one 100km/hr, other 50km/hr. Total distance between the trains starting point is 450km. So the bird is flying to and fro in the train line. The bird continues to do this until the trains collide. How far would the bird have traveled in the meantime?
Answer : Trains will meet when the total distance traveled by both of them is equal to 450 km. We let h = the time each train travels. Therefore
100 * h + 50 * h = 450
Therefore train will collide after, h = 3 hrs. Total distance covered by the bird is 200 * 3 = 600 km.
Reference : Trains and Birds