9. The length, breadth and height of a room are 9m, 8m and 7 m respectively. Find the cost of plastering the four walls and ceiling of the room at the rate of ₹ 7 per sq m. About the author Josie
Given, length of the room (l) = 4.5 m Breadth of the room (b) = 3m Height of the room (h) = 350 cm = 3.5 m And the cost of plastering = Rs. 8perm 2 Therefore, the area of the walls = 2h(l+b) = 2×3.5×(4.5+3) = 7×(7.5) = 52.2 m 2 Area of the ceiling = lb = 4.5×3 = 13.5m 2 Area of the room = 52.5+13.5 = 66m 2 Hence, the cost of plastering = 66×8 = Rs 528 Reply
volume of cuboid = l × b× h
Given, length of the room (l) = 4.5 m
Breadth of the room (b) = 3m
Height of the room (h) = 350 cm = 3.5 m
And the cost of plastering = Rs. 8perm
2
Therefore, the area of the walls = 2h(l+b)
= 2×3.5×(4.5+3) = 7×(7.5) = 52.2 m
2
Area of the ceiling = lb = 4.5×3 = 13.5m
2
Area of the room = 52.5+13.5 = 66m
2
Hence, the cost of plastering = 66×8 = Rs 528