This document discusses three optimization problems: the knapsack problem, traveling salesman problem, and efficiency considerations for algorithms. It defines the knapsack problem as selecting a subset of items with maximum total value that fits in a knapsack of capacity W without breaking items. It defines the traveling salesman problem as finding the shortest route between cities that visits each city once and returns to the starting point. It defines algorithm efficiency as the computational resources and time required to produce results, with more efficient algorithms using fewer resources and time.