Final answer:
The solid with 11 faces and 11 vertices has 20 edges.
Step-by-step explanation:
An icosahedron is a solid with 20 equilateral triangular faces. Each vertex of the icosahedron has 5 triangular faces converging at it. We can use Euler's formula, which states that for any polyhedron, the number of vertices (V), edges (E), and faces (F) are related by the equation V - E + F = 2. Given that the solid has 11 faces and 11 vertices, we can rewrite the equation as 11 - E + 11 = 2. Solving for E, we find that the solid has 20 edges.