Can someone help me out with these questions?

If a dealer bought 20,000 shares of stock at S25 per shares, then sold 5.000 of them at 25.50 per share and 15,000 of them at 25.25 per share. What is the dealer's gross profit? What is the dealer's average bid-ask spread? The spot rate for the Argentine peso is $0.3600 per peso. Over the year, inflation in Argentina is 10 percent and U.S. inflation is 4 percent. If purchasing power parity holds, at year-end the exchange rate should be approximately dollars per peso. You can buy or sell the yen spot at Yen 102 to the dollar. You can buy or sell the yen one-year forward at Yen 104 to the dollar. If U.S. annual interest rates are 4 percent, what must be the approximate one-year Japanese interest rate if interest rate parity holds? You can buy or sell the pound spot at $2.98 to the pound. You can buy or sell the pound 1 year forward at $3.01 to the pound. If U.S. annual interest rates are 5%, what must be the approximate one year British interest rate if interest rate parity holds