Final answer:
The maximum distance the ant can walk on a regular octahedron is 9 units, considering that it walks along 9 of the 12 edges without crossing the same edge twice or passing through the top vertex again.
Step-by-step explanation:
The student is asked to find the maximum distance an ant can walk on a regular octahedron, starting and ending at the top vertex, without traversing the same edge twice or passing through the top vertex again. A regular octahedron is composed of eight equilateral triangles with six vertices. Since the ant must return to the top vertex, it can utilize all the edges except for the three edges that meet at the top vertex; otherwise, she would pass through it again.
To calculate the maximum distance, consider that each edge is traversed once, with the exception of the three edges at the starting vertex. There are 12 edges in total in an octahedron, and the ant will walk across 9 of them (12 edges minus the 3 edges at the top vertex).
As the edge length of each side is one unit, the maximum distance the ant can walk is 9 units (9 edges of 1 unit each).