Mixture density from total mass and volume

Steps:

• Calculate mass of glycerine: 1.3 g/cm³ × 40 cm³ = 52 g.
• Let volume of water added be V cm³; its mass is 1.0 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:

• 80 cm³ satisfies the density formula, as total mass (132 g) divided by total volume (120 cm³) equals 1.1 g/cm³.

Why the others are wrong:

• A: 40 cm³ yields density 1.15 g/cm³, too high.
• B: 8 cm³ yields density 1.25 g/cm³, too high.
• C: 34 cm³ yields density ≈1.16 g/cm³, too high.

Final answer: D