Question

3
The length, breadth and height of a room are 5 m, 4 m and 3 m respectively. Find the
cost of white washing the walls of the room and the ceiling at the rate of
7.50 per m​

Answer 1

Given :

⬤ Length of Room = 5 m

⬤ Breadth of Room = 4 m

⬤ Height of Room = 3 m

To Find :

⬤ Cost of White Washing the Walls of the room and the Ceiling at the rate of Rs 7.50 per m² .

Formula Used :

$\sf[\:{Surface\:Area\:of\:Cuboid=2(lb+bh+hl)-lb}\:]$

Solution :

2 (5×4 + 4×3 + 3×5) - (5×4)

2 (20 + 12 + 15) - (20)

2 (47) - 20

94 - 20

74 m²

Therefore , Area of Room is 74 m² .

Now :

Cost of Ceiling at Rs. 7.50 per m²

74 × 7.50

Rs. 555.00

Hence , Cost of Ceiling is Rs. 555 .