# Determine the number of perfect pairings in a complete bipartite graph Kn,n, in which n disjoint edges are removed.

Determine the number of perfect pairings in a complete bipartite graph Kn,n, in which n disjoint edges are removed.

• This question is admittedly easy, but it still takes some time to write down a polished answer. In general, 2$is very low for any question that requires more than just the result, and even then, it should be immediate. If you want the procedure shown, I think this goes in the 5-10$ range, depending on the level of detail you want.