Assume that in a small open economy where full employment always prevails, national saving is 300. a. If domestic investment is given by I = 400 - 20r, where r is the real interest rate in percent, what would the equilibrium interest rate be if the economy were closed? Why? (2 points) b. If the economy is open and the world interest rate is 10 percent, what will investment be? Why? (2 points) c. If the economy is open, what will the trade surplus or deficit be? What will net capital outflow be? (4 points)