1. The initial capital should be 1 million guilders. If it's US dollars, just deposit one-year US dollars directly, and there will be no problem with the Dutch guilder. 1 ten thousand guilders/current exchange rate of 30,000 = 333,000 USD. If you deposit $330,000 a year, the interest will be $333,000 ×4.5%≈ 1.5 million, 1.5 million × forward exchange rate 315 ≈ 47,000 guilders. And if you deposit 654.38+00,000 guilders directly for one year now, the interest you earn is 654.38+00,000× 2.5% = 25,000 guilders. Compared with the latter case, the profit of the arbitrageur is 47,000-25,000 = 22,000 guilders, which is the net profit.

2. First, buy US dollars in the London market with 6,543,800 pounds, that is, the selling exchange rate is 6,543.8+0.5662 = 654.38+0.5662 million dollars. Immediately after the purchase, I went to the new york market to buy back the pound in dollars, that is, the purchase price of 1566200 USD/pound was 1.5655 ≈ 10004500 pound. Arbitrage profit =100.045-100 = 004500 = 450. (PS: Because the foreign exchange market is large and the mainstream markets are highly unified, it is really rare to use the price difference for white arbitrage, as far as I feel ~)