23.1

a. The call with exercise price $720 costs $55.50. If the stock price at the expiration date is $660, the call expires valueless and the investor loses the entire $55.50. If the stock price is $760, the value of the call at expiration is $760 - $720 = $40, and the investor's profit is $40-$55.50 -$15.50.

b. The put with exercise price $720 costs $52. If the stock price at the expiration date is $660, the value of the put is $720 $660 = $60 and the investor's profit is $60 - $52 = $8. If the stock price is $760, the put expires valueless and the investor loses the entire $52.