Question: Calculate the NPV at 12%

\begin{tabular}{l|cccc} & Project A & Project B & Project C & Project D \\ \cline { 2 - 5 } net investment & ($50,000) & ($50,000) & ($50,000) & ($50,000) \\ CF & - & - & $20,000 & $20,000 \\ CF & - & $30,000 & $20,000 & $30,000 \\ CF & - & - & $20,000 & $10,000 \\ C5 & - & $70,000 & $20,000 & $10,000 \\ C5 & $90,000 & - & $20,000 & $10,000 \end{tabular}