You have purchased one call and one put option on the same underlying stock. The strike price of the call option is 195 SEK and the strike price of the put option is 205 SEK.

a)What is the minimum payoff of your portfolio on the expiration date?

b)Which prices of the underlying stock on the expiration date yield this minimum payoff? c)What is the minimum total amount we must have paid in premiums for this portfolio?

A tip here is to remember that there must be someone selling these options to us. Also note that we do not have enough information to actually compute the option price ??

1) On the exercise date the portfolio is worth at least ?

2) The stock price can vary between ?

3) The total premium cannot be less than ?

How should I start ?

What formulas should I use ?

It is hard to know how to solve the problem.