Can a polyhedron have 10 faces, 20 edges and 15 vertices?
Number of faces = F = 10
Number of edges = E = 20
Number of vertices = V = 15
Any polyhedron satisfies Euler's Formula, according to which, F + V - E = 2
For the given polygon,
F + V - E = 10 + 15 - 20
= 25 - 20
= 5 ≠ 2
Since Euler's formula is not satisfied, such a polyhedron is not possible