Solve the following ILP problem, a knapsack problem, using the branch-and-bound algorithm, and stating an "upper bound" and a "lower bound" at each node of your branch-and-bound process. Marimize z = 10a1 + 20r2 + 30.r3 subject to: 5x1 + 6x2 + 7a3 < 15 *1, 2, 3 E {0, 1}