Mixture density via mass conservation

Steps:

• Mass of glycerine: 1.3 g/cm³ × 40 cm³ = 52 g.
• Let volume of water added be V cm³; its mass is 1 g/cm³ × V = V g.
• Total mass = 52 g + V g; total volume = 40 cm³ + V cm³.
• Set up equation: (52 + V) / (40 + V) = 1.1; solve to get V = 80 cm³.

Why D is correct:

• The density formula for mixtures (total mass / total volume) directly yields 80 cm³ when solved, assuming additive volumes.

Why the others are wrong:

• A: 40 cm³ gives density 1.15 g/cm³, higher than 1.1 g/cm³.
• B: 44 cm³ gives density ≈1.14 g/cm³, higher than 1.1 g/cm³.
• C: 52 cm³ gives density ≈1.13 g/cm³, higher than 1.1 g/cm³.

Final answer: D