5 perfectly symmetrical polyhedrons with 4, 6, 8 12, 20 faces.Find expected value for dies made in each shapes

Question

There are only 5 perfectly symmetrical polyhedrons, the tetrahedrons(4faces), the cube(6faces), the octrahedron(8faces), the dodecahedrons(12faces) & icosahedrons(20faces), Calculate the expected value for dies made in each of these shapes?

Answer 1

As the previous poster said, you don't have enough information. If you have n-sided polyhedra, are the sides numbered 1 to n? Is the expected value in reference to a throw of the dice? If so, are we talking about two dice?

For two dice with the sides numbered 1 to n, the answer is n + 1.

Answer 2

O.K. , I am probably missing something.
Lets have a look at the icosahedron, there are 20 faces, you can either number them 0 to 19 or 1 to 20 , as regular cubic dice are numbered 1 to 6 I suppose 1 to 20 would be more traditional. Arrange them so that opposite faces add up to 21 - done, you have a twenty sided die.

Now do the same for all the others - expected value is the mean throw? which is (n+1)/2 where n is the number of sides.