Chaptee 4 the ε o many ermhs o5. have a.) esoctly 15 inversions b)exactly 14 inversions c.) exactly 13 inversions r b soluhons: how many permutation have exactly 15 inversions, 14,13. unerent permutations have different inversion sequences. theorem 4.2.1 let b, b n be a sequence of integers satisfying then there erists a unique permutation of 2.) whose inversion sequence is bi, b,bn proof. we describe two methnds 6 i don't understand how to get the following solutions for the inversion questions.