Final answer:
Without additional information, we infer the answer by reasoning through the options provided. Since Wendy's trip was 500 miles in total and the train's average speed was 65 mi/h, the only option where the train does not exceed the total distance is 6 hours on the train.
Step-by-step explanation:
The student's question involves calculating the time spent on a train given the average speed of the train and the total distance of the trip. The average speed of the train is given as 65 mi/h, but the question does not provide enough information to determine the duration of the train part of the trip directly. However, we can reason through the options provided (3, 4, 5, or 6 hours) and eliminate any that would result in the train covering more than the total trip distance of 500 miles.
For example, at 65 mi/h, spending 6 hours on the train would mean:
65 mi/h * 6 h = 390 miles
This is the only option that does not exceed the total distance, so we can infer that Wendy spent 6 hours on the train.