Answer:
5.2 hours, or 5 hours 12 minutes
Explanation:
The distance is the same in both cases. Since distance = rate (time),
time = distance / (rate).
Here, (6 hr)(52 mph) = (time)(60 mph, or
312 mi = (60 mph)(time), which gives us
(time) = (312 mi) / (60 mph) = 5.2 hours, or 5 hours 12 minutes