you purchased a call option on the s&p 500 (spx) with a strike of $1,500. you paid a premium of $15. you also wrote an spx call option with the same maturity date and a strike if $1,450. you received a premium of $14.50. at maturity, what is your total payoff if spx is trading at $1,475? (enter your answer in $ accurate to two decimal places.)