A polyhedron is having 8 vertices and 12 edges. How many faces of it are there?

Number of vertices (V) = 8
   Number of edges (E) = 12
Let the number of faces = V
Now, using the Euler's formula
                   F + V = E + 2
we have
                   F + 8 = 12 + 2
              F + 8 = 14
                  F =  14 - 8 
                 F = 6
  Thus, the required number of faces = 6.