Of Trains and Bees
Two train engines under a controlled technical experiment begin at a speed of 100 kph in the opposite direction in a tunnel. A supersonic bee is left in the tunnel which can fly at a speed of 1500 kph.
The tunnel is 400 kilometers long. When the train engines start running on a constant speed of 100 kph, the supersonic bee starts flying constantly from one train engine towards the other. As soon as the bee reaches the second train engine, it starts flying back towards the first train engine.
If the bee keeps flying to and fro in the tunnel till the trains collide, how much distance will it have covered in total?