A Restaurant Supply Company Must Ship at Least 80 Cases $\$ 9.60$

A restaurant supply company must ship at least 80 cases of seafood to two midwest restaurants. Each restaurant can accommodate at most 80 cases of seafood. Restaurant A already has 20 cases of seafood on hand, while restaurant B already has 16 cases. It costs $\$ 9.60$ to ship a case of seafood to restaurant A and $\$ 8$ to ship a case of seafood to restaurant B. How many cases should be shipped to each restaurant to minimize cost? What is the minimum cost?