Consider the case of a U.S. investor holding dollars and deciding whether to invest in Japanese treasury bills or in U.S

[answerhappygod]

Consider the case of a U.S. investor holding dollars and
deciding whether to invest in Japanese treasury bills or in U.S.
treasury bills. Assume that the investor wants to end up holding
dollars. What are the three methods available to this investor to
turn present dollars into future dollars? In your answer present an
equation that shows the return per dollar invested under each
method. Which of these methods is the riskiest and why?