Apple is currently at $270. You buy a call on Apple with a strike price of $275, and you write a call on apple with a call of $280.

What is the largest payoff that you could receive from this strategy?

What is your payoff if at the time of expiration, Apples price is $279?

Is this a strategy which should have cost you money to enter, or a strategy which you should have received a premium for entering? (please write one of these two as the answer: cost premium )