8. Knapsack Problem Suppose that a 20-1b knapsack is to be filled with three types of items. The weight and benefit of an item depends on type, as shown in the table below. In order to maximize total benefit, how should the knapsack be filled if at least one item from each type should be included. Formulate and solve it by Dynamic Programming. Type (n) 1 2 3 Weight (w.) 4 Benefit (en) 10 7 12