20-1 Calculate the dollar gain or loss on Treasury bond futures contracts ($100,000) per contract for the following transactions. In each case the position is held 6 months before closing it out. a. Sell 10 T-bond contracts at a price of 8280 and buy 10 at 7612. b. Sell 10 T-bond contracts at a price of 80-14 and buy 10 at 77. c. Buy 15 T-bond contracts at 6210 and sell 15 at 6424. d. Sell one T-bond contract at 7014 and buy one at 7808