Assume we have two trains moving on the same track. These trains are approaching each other head-on meaning that Train A is moving towards Train B & vice versa. The track these trains are on has a distance of 120 km. Train A has a speed of 26.6 km/hour and Train B has a speed of 19.7 km/hour.
Now on top of Train A, there is a little bird that is flying with a speed of 33.4 km/hour. The bird flies from Train A to Train B and back. He keeps doing this until both trains approach each other.
The question is: How much distance has the bird flown once both trains approached each other?