In a practical problem, a car travels 60 km/h and a truck travels 40 km/h. If they start from the same point at the same time, how far apart will they be after 2 hours?
Answer: C. 100 km
After 2 hours, the car travels 120 km and the truck travels 80 km, so the distance apart is 120 km - 80 km = 40 km.