To answer this question, we need to have into account the ratio between the chocolate and the nuts. This ratio is:
That is, simplifying the ratio, we have 2 parts of chocolate and 3 parts of nuts. This ratio must be the same for the tablespoon. Then, if we have 18 tablespoons of nuts, then we can pose the situation as follows:
Therefore, we need 12 tablespoons of chocolate to follow the recipe for the party.