How many elements in a field of size $3^4 (81)$ have multiplicative order $20$?

173 Views Asked by At

I'm looking at the fact that the set of multiplicative inverses has order 80 and is cyclic. Since 20 divides 80 can we say using euler's function it is 8? It seems too simple for the number of points the question gets. I'm also getting confused with the fact that the order of an element divides the order of the group (and a field is a group) but 20 doesn't divide 81?