John draws a regular five pointed star in the sand, and at each of the 5 outward-pointing points and 5 inward-pointing points he places one of ten different sea shells. How many ways can he place the shells, if reflections and rotations of an arrangement are considered equivalent?
I am not too sure about the reflections part of it.
First place a shell down anywhere, call it A, now there are 9 shells left so
9! takes into consideration of the rotation part
Maybe for the reflection you just divide by 2 becasue there is only one axis of symmetry through A
So maybe the answer is 9!/2
If you have access to the answers can you check and comment on whether this is the same.?