Given that Hometown Care, Inc.'s stock is currently selling for $40 a share, calculate the amount of money that Calvin Haskins will make (or lose) on each of the following transactions. Assume that all transactions involve 100 shares of stock, and ignore brokerage commissions.
a. He short-sells the stock and then repurchases the borrowed shares at $50.
b. He buys the stock and then sells it sometime later at $50.
c. He short-sells the stock and then repurchases the borrowed shares at $25.