a$)$ If the consumer price index for the United States rises from $350$ at the end of a year to $365$ at the end of the next year, how much inflation was there in the United States during that year?

b$)$ Consider the case that inflation had been $6\mathrm{.}5\%$ in the euro$-$area in that year. How should the euro$/$USD exchange rate change on the basis of the Purchasing Power Parity.