40. Solving a chemistry problem

5. Why do dolphins have sweet tears? Dolphin tears contain sugars - galactose and fructose. Carbohydrate-protein, reminiscent of the protein of a chicken egg, tears serve as a lubricant. Dolphins cry to see better and swim faster. Set the molecular formula of fructose, which gives dolphin tears a sweet taste, if the mass fractions of elements in it are: 40.0% (C), 6.6% (H), 53.4% (O).