8 persons can stay in a cubical room. Each person requires 27 m³ of air. The side of the cube is

6m

According to the question, each person requires 27 m³ of air
Volume of air required by 8 people = 8 × 27 = 216 m³
We know, Volume of the cube = (side of the cube)³
⇒ 216 = (side of the cube)³
⇒ side of the cube = ∛216
∴ side of the cube = 6 m
Hence, the length of the side of cube is 6 m.