The Emerald Investment Group is considering investing in six projects. The expected net present…

➤ Why express “Among projects 1, 3, and 4, two must be selected” as an equality?
Use X1 + X3 + X4 = 2. This equality enforces exactly two of those three projects. With Xi binary, the constraint prevents selecting fewer or more than two. It integrates directly into the integer program and interacts with the budget and other logical constraints to ensure feasibility.