3) Suppose that you need to pack a knapsack for this road trip. Determine the values and weights of six favorite items of yours and also indicate the weight limit of your knapsack in kilos (please make sure that the sum of the weights of six items is greater than the weight limit of the knapsack so that you have a problem of choosing some of the items). a) Formulate this problem as a 0-1 knapsack problem (define decision variables, identify the objective function, constraints, and sign restrictions if any) b) Solve the problem using branch and bound approach (solve manually and show your iterations).