Two trains , 100 km apart , travel towards each other on the same track . One train travels at 40 km/hr, the other travels at 60 km/hr . A bird starts flying at a speed of 90 km/hr , at the same location of the faster train . When it reaches the slower train, it turns around and flies in the opposite direction at the same speed . when it reaches the faster train , again it turns around and so on . When the two trains collide , how far has the bird flown ?

Two trains , 100 km apart , travel towards each other on the same trac

1.	Two trains , 100 km apart , travel towards each other on the same track . One train travels at 40 km/hr, the other travels at 60 km/hr . A bird starts flying at a speed of 90 km/hr , at the same location of the faster train . When it reaches the slower train, it turns around and flies in the opposite direction at the same speed . when it reaches the faster train , again it turns around and so on . When the two trains collide , how far has the bird flown ?
Answer» 90 km 45 km 180 km 135km Solution :Since the trains are 100 km apart , and the trains are TRAVELLING TOWARDS each other at 40 and 60 km/hr , the trains will COLLIDE in one hour . The bird must be flying at 90 km/hr during this TIME , so the bird travels 90 km .