Explanation:
so, the only thing we know is that in 1.5 hours 915 miles were traveled.
is this an airplane ? it is pretty fast.
anyway, yes, this indicates a speed of 610 mph, as we need to divide both, speed and time, by 1.5 to get mph (miles per 1 hour).
now, is the speed constant over time ? are we going the whole 2.5 hours with 610 mph ?
because I don't see any information about that.
assuming it is the case, then the speed is 610 in all lines.
and in 1 hour, we go then 610 miles, of course.
in 2 hours 610×2 = 1220 miles
in 2.5 hours 610×2.5 = 1525 miles