**Category:** Organic Chemistry  
**Subtype:** Combustion Reactions and Stoichiometry  
**Problem Description:** This problem involves the complete combustion of a mixture of an alcohol and two amines. It requires calculating the mass percentage of one of the amines in the mixture based on the stoichiometry of the combustion products (N₂, H₂O, and CO₂) and the given relationships between the components of the mixture. Specifically, it asks for the mass percentage of amine Y in the mixture E.