3. In this question assume all dollar units are real dollars in billions, so, for example, $150 means $150 billion. It is year 0. Argentina thinks it can find

$150 of domestic investment projects with an MPK of 10% (each $1 invested pays off $0.10 in every later year). Argentina invests $84 in year 0 by borrowing $84 from the rest of the world at a world real interest rate r

* of 5%.

There is no further borrowing or investment after this.