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 cmrespectively. Find the cost of plastering at the rate of Rs 8 per sqm

Answer 1

Convert all units to m:

350 cm - 3.5 m

Find the area of the ceiling:

Area = Length x Breadth

Area = 4.5 x 3 = 13.5 m²

Find the area of the 4 walls:

Area = Perimeter of the ceiling x height

Area = 2 (4.5 + 3) x 3.5 =  52.5 m²

Find the total area:

Total area = 13.5 + 52.5 = 66 m²

Find the cost:

1 m² = Rs 8

66 m² = 66 x 8 = Rs 528

Answer: The cost of plastering is Rs 528

Answer 2

area of 4 wall is 2(l +b)×h

+ are of ceiling is (l×b)

2(4.5 +3)3.5m + (4.5×3)

=>52.5 m² + 13.5 m²

=> total area 66m²

total cost => 66m² × 8 per/m² = 528

total cost is 528

Thank you