What is the answer to this question

38 kg/m³

0.038 g/mL

Explanation:

Volume of a cube is the side length cubed.

V = s³

Given s = 0.65 m:

V = (0.65 m)³

V ≈ 0.275 m³

The mass is 10.5 kg.  The density is the mass divided by volume:

ρ = (10.5 kg) / (0.275 m³)

ρ ≈ 38 kg/m³

Or:

ρ ≈ 0.038 g/mL

answer: they produce more slow than unicellular organisms.