1. Three-month European put options with strike prices of $50, $55, and $60 cost $2, $4, and $7, respectively.
   1. How can one create a butterfly spread using these options?
   2. Please draw the payoff and profit diagrams of this butterfly strategy.
   3. What are the maximum gain and maximum loss of the butterfly spread created using these put options?
   4. For which two values of S_T does the holder of the butterfly spread break even (with a profit of zero), where S_T is the stock price in three months?