For the next 5 questions (from the Chapter 12 slides), consider a stock that moves according to a following tree over the next 12 months, where each of the 2 steps is 6 months, and there are only 2 possibilities (2 possible moves) for the stock at each node. Today the stock price is $20. Risk-free rate is 10% annually, and assume that any and all options written on the stock are American and have an exercise price of $21. 24.2 19.8 16.2 20 18 5. What is the current (today's) delta of a call option expiring in 6 months? 6. How many shares would an investor need to combine today with writing1 call option expiring in 6 months in order to form a riskless portfolio? 7. The value of a 6-month call option today is: 8. Assuming that 6 months from now the stock is at S18, what is the value of a 6-month call option at that point in time (meaning, the value of an option that expires a year from now)? 9. Assuming that 6 months from now the stock is at S18, what is the value of a 6-month put option at that point in time (meaning, the value of an option that expires a year from now)