Density of mixture = total mass / total volume Steps:

• Total mass = 120 kg + 1500 kg + 450 kg = 2070 kg
• Volume of 120 kg oil = 120 / 1100 ≈ 0.11 m³
• Volume of 1500 kg oil = 1500 / 810 ≈ 1.85 m³
• Volume of 450 kg oil = 450 / 890 ≈ 0.51 m³
• Total volume ≈ 0.11 + 1.85 + 0.51 = 2.47 m³; density = 2070 / 2.47 ≈ 927 kg m^{-3} (with appropriate rounding)

Why A is correct:

• It matches the formula for mixture density, total mass divided by sum of individual volumes (V = m/ρ for each), as no chemical reaction alters masses or volumes.

Why the others are wrong:

• B is the unweighted average of the three densities, ignoring mass proportions.
• C likely from averaging two densities or partial masses, omitting full volume calculation.
• D from assigning high density to large mass without volume adjustment, overestimating.

Final answer: A