Harriet Tubman helped the union army because she had inside information.
Answer: The two trucks will be 339.5 miles apart after 3.5 hours.
Explanation:
Let x =Time taken(in hours) by both trucks when they 339.5 miles apart.
Distance = Speed x Time
Distance traveled to North = 48x miles
Distance traveled to South = 49x miles
Total distance = 48x+49x = 97x miles = 339.5 miles [given]

Hence, the two trucks will be 339.5 miles apart after 3.5 hours.