OK, I want to increase my berries by 20, but to do that I have to decrease my rabbits by one so the opportunity cost, assuming we are in scenario E the opportunity cost of 20 more berries is one rabbit now this, right over here, is not a marginal cost cause I am talking about the cost of 20 more units not just one if I want to write this as a marginal cost of one more berry then I could just say, well 20 berries is one rabbit you could say, you could essentially divide both sides by 20 so one more berry and I will assume for those who want to get more technical, its somewhat linear right over here one more berry, if we divide both sides by 20 is 1/20 of a rabbit so if I go for one extra berry, sitting in scenario E on average, I am going to get 1/20 less of a rabbit and when I phrase it this way, it is being phrased as a marginal cost now, for those who want to get a little technical this is a curve, right over here, so it might not be exactly this we can't just, well, I don't want to get too technical for the sake of this one right over here, this is a safe way to think about it the opportunity cost of 20 more berries is one rabbit but if we assume that it's somewhat linear right over here its not so curved, it's somewhat of a line between those two points then the opportunity cost of 1 berry is 1/20 of a rabbit or the marginal cost of an extra berry is 1/20 of a rabbit and we could do it at different points on this curve and I actually encourage you to do, based on the data that we have in this table that we constructed in the last video, and maybe this curve think about what the opportunity cost is in the different scenarios if you're in scenario B, and if you want an extra rabbit how much is that going to cost you in terms of berries or if you want more berries, what is that going to cost you in terms of rabbits?