=+b. David approaches Diane for a favor. David says that the solar lighting project is a pet project of his boss, and David really wants to get the project approved to curry favor with his boss. He suggests to Diane that they roll their two projects into a single proposal. The cash flows for this combined project would simply equal the sum of the two individual projects. Calculate the NPV of the combined project. Does it appear to be worth doing? Would you recommend investing in the combined project?