8. Can a polyhedron have 10 faces, 20 edges and 15 vertices?
Checking using Euler's Formula:
F + V = E +2;
Given that F = 10, V = 15 and E = 20 so,
Putting in equation: 10 + 15 = 35 and 20 +2 = 22
Hence, given polyhedron having 10 faces, 20 edges and 15 vertices is not possible.