Hi Guru,
I think I have solved the problem
The fly will have covered 130 miles.
Why?
The movement of the first train can be described by the equation s=40*t
The movement of the second train can be described by the equation s=200-60*t (it starts 200 miles away and runs in the opposite direction)
The two trains will crush when 40*t=200-60*t, that is t=200/100=2 hours
Meanwhile, the fly will have covered s=65*t=65*2=130 miles
Is it OK :?:
JC