<PRE><B>Question 663630</B>
Train I speed = 55 km/h
Train II speed = 70 km/h

They are moving towards each other
so add up the speeds.
combined speed = 125 km/h

Distance = 100 km

Time taken by the trains to meet will be t= d/s

100/125 = 4/5 of an hour

During this time the fly is flying continuously.
speed = 100 km/h

distance traveled by Fred = speed * time
100 * 4/5 = 80 km

m.ananth@hotmail.ca</PRE>