(a) How many paths of length 4 are there in the complete graph K7? (Remember that a path such as v1 → v2 → v3 → v4 → v5 is considered to be the same as the path v5 → v4 → v3 → v2 → v1.)
(b) Let m, n ∈ Z+ with m < n. How many paths of length m are there in the complete graph Kn?