Question

find the volume of cubical box . if the cost of painting of outer surface is rs 1440 at the rate rs 15 per mcube

Answer 1

Surface of a cubical box=6(side²)

1)We have to calculate the surface of this cubical box.
Rate=cost of painting / surface  ⇒surface=cost of painting/rate

Data:
Rate=$15/m²
cost of painting=$1440

Surface=$1440/($15/m²)=96 m²

2)We find out the length of the side:

Surface of a cubical box=6(side²)

Data:
Surface of a cubical box=96 m2

Therefore:
96m²=6 (side²)
side²=96 m²/6
side²=16 m²
side=√(16 m²)=4 m

3) We find the volume of a cubical box.
volume=(side³)
volume=(4 m)³
volume=64 m³

Answer: the volume of this cubical box would be 64 m³.