Compare the space complexity of adjacency lists and matrices for graphs with varying edge densities (e.g., sparse vs. dense).

Derive the exact space requirements (in terms of V and E) for both representations and explain why one may be more efficient than the other in specific scenarios.

Given a graph with 10,000 vertices and 15,000 edges, calculate the memory usage (in bytes) for both adjacency list and matrix representations, assuming each vertex/edge reference occupies 4 bytes.