Solution: ‘Value-additivity principle’ implies in NPV method of capital budgeting. According to the value additivity principle in NPV, the value of the entire firm or a larger project is equal to the sum of all smaller NPVs of projects. In other words, the larger NPV of an investment project is the sum of all smaller NPVs. The NPV of a collection of independent projects will equal the NPV of all independent projects.
i.e. NPV (A+B) = NPV (A) + NPV (B)