Question

The length of a hall is double its breadth. Its height is 3 m. The area of its four walls (including doors and windows) is 108 m², find its volume.

Answer 1

Let the breadth be x
and the length be 2x
Height = 3 m
Area of four walls = 108 m²

⇒ 2(l + b)h = 108

⇒ 2(2x + x)3 = 108

⇒ ${\displaystyle 6\times 3x=108}$

⇒ ${\displaystyle 3x=\frac{108}{6}}$

⇒ ${\displaystyle x=\frac{18}{3}=6}$m

∴ Breadth = x = 6 m

and length = 2x = 12 m

Hence, Volume = ${\displaystyle l\times b\times h}$

= ${\displaystyle 12\times 6\times 3}$

= 216 m³