mikester2,

I never was much good at math(S)

You have: Distance to travel in metres / speed in metres per second which I would guess to be

750 / 200,000,000 which is 0.00000375 seconds, which I suppose are 3.75 microseconds?

Given that the speed of light is 299,792,458 metres per second, this implies some resistance/impedance in the cable, which sort of makes sense?

What you do is convert all the measurements to common denominators and the answer "drops out"? In this case we have metres and seconds for distance and time?

You are lucky I do not teach you: I would have asked the "speed of light in furlongs per fortnight" ..............

the speed of light = 1.8026175 × 10 to the 12 furlongs per fortnight

Just type the bit between the inverted commas into google and hit search..........it has a calculator.

Cheers