Let t = time it takes to go from point X to point Y
Then, t + 0.75 = time to go from Y to X (45 min = 0.75 hr)
Distance = (Rate)(Time)
Since the distance from X to Y is the same as the distance from Y to X,
we have: 480t = 460(t+0.75)
480t = 460t + 345
20t = 345
t = 17.25 hours
Time from Y to X = t + 0.75 = 18 hours
One-way distance = 460(18) = 8280 miles