Final answer:
The displacement of the runners is 0 miles since they returned to their starting point, which means there was no change in position.
Step-by-step explanation:
The displacement of the runners who started at their school ran 6 miles north and then returned to their starting point is 0 miles. Displacement is a vector quantity that describes the change in position of an object. In this case, because the runners ended at the same place they started, there was no change in their position, and thus their displacement is 0 miles. They have returned to their original starting point, regardless of the distance they ran. Displacement encapsulates direction and magnitude, clarifying that despite the physical distance traversed, the runners' final location aligns precisely with their starting point, resulting in a displacement of 0 miles.