Question

The walls and ceiling of a room are to be plastered. The length, breadth and height of the room are 4.5 m, 3 m, and 350 cm respectively. Find the cost of plastering at the rate of Rs 8 per m².

Answer 1

Given,

Length of the room `(l)` = 4.5 m

Breadth of the room `(b)` = 3 m

Height of the room `(h)` = 350 cm = 3.5 m

And the cost of plastering = Rs 8 per m²

∴ Area of the walls = `2h(l + b)`

= 2 × 3.5 × (4.5 + 3)

= 7 × (7.5)

= 52.5 m²

Area of the ceiling = `lb`

= 4.5 × 3

= 13.5 m²

Area of the room = 52.5 + 13.5

= 66 m²

Hence, the cost of plastering = 66 × 8 = Rs 528