This question is one I found in a competitive exam paper, and has two solutions: one simple and one complex.
A train starts from the east end of a 200 km long east-west track at 50 km/h. At the same time, a bird starts flying in a straight line from the west end along the same track at 60 km/h. When the train and bird meet, the bird immediately turns around and goes to its starting point, then again turns around and meets the train. This goes on till the train reaches the bird's origin point. How much total distance has the bird covered?
Both the bird and the train neither speed up nor slow down during this entire time.
Bonus for posting more than one solution.