In the country Constantania, suppose the velocity of money is always the same. Last year, the money supply was $2 billion and real GDP was $5 billion. This year, the money supply increased by 6 percent, real GDP by 4 percent, and nominal GDP is $6.5 billion. a) Calculate the velocity of money and the price levels in the two years, and then calculate the inflation rate. b) Calculate the inflation rate using the formula AM/M + AV/V = AP/P + AY/Y, where the Greek letter A represents a change and the ratio AM/Mx 100 is the percentage change (or the rate of change) in M. Compare this result with the result you obtained in part a. Why could there be some difference? c) What is the difference between commodity money and fiat money? Why do people accept fiat currency in trade for goods and services