Let's complete the missing information:
1. GDP of Potterland in billions of US$: 311/22 (GDP in billions of domestic currency/Exchange rate for domestic currency to US$) = 14.14 billions of US$
2. GDP of Grangerland in billions of US$: 41/11 (GDP in billions of domestic currency/Exchange rate for domestic currency to US$) = 3.73 billions of US$
3. Exchange rate for Weasley Island domestic currency to US$: 799/209 (GDP in billions of domestic currency/GDP in billions of US$) = 3.82 Icesticks to US$
Now, let's answer the questions:
1. What is the GDP of Grangerland in billions of Lightrocks? We take GDP of this country in billions of US$ and multiply by Exchange rate of Potterland Lightrocks to US$ to get this result. (3.73 x 22) = 82.06 billions of Lightrocks
2. What is the exchange rate for Icesticks to U.S. dollars? We already have this result, we calculated it on missing information 3 = 3.82 Icesticks to US$
