In 1998, a liter of Scotch cost $22.84 in New York, S$69 in Singapore,
and 324-rubles in Moscow.

a. If the law of one price held, what was the exchange rate between
U.S. dollars and Singapore dollars?  Between U.S. dollars and rubles?

b.The actual exchange rates in 1992 were S$1.63 = US$1 and 250 rubles
= US$1.  Where would you prefer to buy your scotch?

The law of one price states that "...the price in dollars is the same
as the price in foreign currency, after currency translation."

"Going for the Gold" by John B. Hussman, Hussman Econometrics (October
1999), http://www.hussmanfunds.com/html/gold.htm

Therefore, the exchange rate between US dollars in Singapore dollars
would be 3.02 Singapore dollars to the US dollar (S$69/$22.84) and the
exchange rate between dollars and rubles would be 14.19 rubles to the
US dollar (324 rubles/$22.84).

Using the provided exchange rates, the S$69 bottle of Scotch would
cost $42.33 and the 324 ruble bottle of Scotch would cost $1.30. 
Therefore, assuming the price had not changed drastically in local
currency, it would be most attractive to purchase Scotch in Moscow.

Sincerely,

Wonko