Step-by-step explanation:
the speed is 130 miles / hour.
that means the train travels 130 miles in 1 hour.
so, the question is, how far is it traveling. when it is going with that speed for 6 hours ?
well, 130 × 6 = 780 miles.
formally, speed is "distance / time".
multiplying this by some time, we have then an expression of "(distance / time) × time", which is then simply "distance".
