Consider two persons, Sam and Alex. Suppose in a 24-hour period, Sam can make either 25 bookmarks or 12 pairs of slippers, while Alex can make either 15 bookmarks or 40 pairs of slippers. If they were to specialise and trade, what would be the maximum relative price Sam would pay Alex (i.e. the maximum number of goods Sam produced that he is willing to offer to Alex in exchange for 1 unit of the goods Alex produced)?