[
  "A ratio compares two quantities. Identify the mass used and the mass left first.",
  "Mass used = 3 kg. Mass left = 10 kg - 3 kg = 7 kg. Ratio of mass used to mass left = 3 : 7.",
  "The ratio of sugar used to sugar left is 3 : 7. Answer: 3 : 7 (option B)."
]