maths
posted by avinash on .
Two trains are on the same track a distance 300 km apart heading towards one another, One at a speed of 150 km/h and other at a speed of 50 km/h. A fly starting out at the front of one train, flies towards the other at a speed of 600 km/h. Upon reaching the other train, the fly turns around and continues towards the first train. How many kilometers does the fly travel before getting squashed in the collision of the two trains?

How fast is the fly? (600km/h)
How long has the fly been flying before the trains collide? (300km/(150+50))=1.5 hours
So how far has the fly travelled? 
900km