You have to choose how to invest a sudden windfall, and the two investments between which you are trying to decide have the following terms. Investment A will pay a monthly dividend of
$100 along with 0.1% of the principal (the principal is the amount invested). The other pays a
straight 0.2% of the principal.
Which of these is likely to be best for small amounts of principal?
Which is likely to be best for large amounts? Explain.
Find the boundary - the amount at which the two pay the same.