If the total surface area of a cube is 864 square cm, find the volume of the cube ?

Answer: Option A

Each edges of cube = a cm
∴ Total surface area of cube = 6a²
⇒ 6a² = 864
⇒ a² = $$\frac{864}{6}$$ = 144
⇒ a = $$\sqrt{144}$$ = 12 cm
∴ Volume of cube :
= a³ cm³
= (12 × 12 × 12) cm³
= 1728 cm³