please show step by step. no excel formula. thank you

At the beginning of the year, a U.S. investor chooses to invest $200,000 in a German company Common stock. At the beginning of the year, the spot rate is $1.15/ and the stock price is 40/share, At the end of one year the spot rate is $1.25/6. a) At the end of the year, the investor sells his shares at an average price per share of 50. What is the investor's average rate of return before converting the gains into dollars? b) At the end of the year, the investor sells his shares at an average price per share of 50. What is the investor's average rate of return after converting the gains back into dollars