Suppose you purchased a share in the USA for $$12\mathrm{.}50$ and later sold the investment for $$14\mathrm{.}10.$ The USD depreciated over the period from $1$AUD $=\mathrm{.}73$ USD to $1$ AUD $=\mathrm{.}75$ USD.

A$)$ Calculate the Australian dollar return on the investment.

B$)$ At what ending exchange rate would the Australian dollar return on the investment be reduced to zero?