Problem: A cube is made by soldering twelve -inch lengths of wire properly at the vertices of the cube. If a fly alights at one of the vertices and then walks along the edges, the greatest distance it could travel before coming to any vertex a second time, without retracing any distance, is:
Answer Choices:
A. 24 in
B. 12 in
C. 30 in
D. 18 in
E. 36 in
Solution:
The longest path covers edges, and (inches).