# How to find total number of minimum spanning trees in a graph with n edges?

I had this question on my final exam so sadly I don't have the question but as far as I remember, the question was saying:

How many minimum spanning trees does a graph with 20 edges have.

I know that we can find minimum spanning trees with algorithms like Prim's algorithm etc. But how can we know the total number of minimum spanning trees in a graph with no figure given in the question (text only)?

(A clique on seven vertices has 21 edges, which is only one more than your graph is allowed. If all the edge weights were the same, every subtree would be an MST and, by Cayley's formula, there are $7^5=16807$ different trees with seven vertices.)