Q. Use put-call parity to show that the cost of a butterfly spread created from European puts is identical to the cost of a butterfly spread created from European calls.
My problem with this question is what they mean by 'cost' of the spread. Is that the total you're paying for the options to create the spread?
And, if so, won't the put-call parity rule only work if you are buying puts and calls on the same options?
Thanks for any help!