A stock price is currently $$\$ 40$$. Over each of the next two 3-month periods it is expected to go up by $10 \%$ or down by $10 \%$. The risk-free interest rate is $12 \%$ per annum with continuous compounding. (a) What is the value of a 6-month European put option with a strike price of $$\$ 42$$ ? (b) What is the value of a 6-month American put option with a strike price of $$\$ 42$$ ?