Hi,everyone! Does anyone know how to compute number of paths of length 2 in a complet bipartit graph Kn,m? I search on Google and I have found only this one proof:(http://math.colorado.edu/~kstange/graph-theory-worksheet-solns.pdf),last page,exercise 6!I am not sure about the paths which have only one edge!For example,let be vertex A in the first subset and the vertices B,C in the second one!The above proof takes in counting the paths A-B-A,B-A-B,A-C-A,C-A-C.......This is right?