Increase or decrease in percentage____%

If the price of silver in England is 6.85 per ounce, what is the expected price of silver In the United States if the spot exchange rate is $1 = 0.5173? The Russian financial crisis of 1998 caused its currency to be dramatically devalued. What is the percentage change in value of a $220 million investment in Russia when the exchange rate changes from $1 = 4 rubles to $1 =16 rubles