Density of mixture from total mass and volume

Steps:

• Mass of water: 1.5 m³ × 1000 kg m⁻³ = 1500 kg
• Mass of alcohol: 0.5 m³ × 800 kg m⁻³ = 400 kg
• Total mass: 1500 kg + 400 kg = 1900 kg
• Density of mixture: 1900 kg / 2 m³ = 950 kg m⁻³

Why D is correct:

• Density is defined as total mass divided by total volume, yielding 950 kg m⁻³ for the mixture.

Why the others are wrong:

• A: Underestimates by averaging densities without weighting by volume.
• B: Results from unweighted average of 1000 and 800 kg m⁻³.
• C: Arises from error like incorrect total mass (e.g., 1880 kg).

Final answer: D