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 square metre.

Answer 1

Given,

Length of room = 4.5 m

Breadth of wall = 3 m

Height of wall = 350 cm = \(\frac{350}{100}\) = 3.5 m

So,

Area of ceiling + area of walls = l x b + 2(l x h + b x h)

= 4.5 x 3 + 2(4.5 x 3 x 3.5) = 13.5 + 2(15.75 + 10.5)

= 13.5 + 52.5 = 66 m²

Cost of plastering 1 m² area = Rs.8

∴ Cost of plastering 66 m² area = 66 ×8 =Rs.528