Question

The walls and ceiling of a room are to be plastered. The dimensions of the room are 4.5 m × 3 m × 50 cm. Find the cost of plastering at the rate of ₹ 12/m2 ​

Answer 1

Answer:

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

Step-by-step explanation:

hope its helpful

Answer 2

☀ Given that: The dimensions of the room are 4.5m × 3m × 50cm and the walls, ceiling of that room are to be plastered.

   Need to find: Cost of plastering at the rate of Rs. 12/m²

Must Understand:

• This room is in the form of cuboid as length, width, height are not same in measure.
• The area to be plastered for walls is the Lateral Surface Area.
• Area of ceiling alone will be area of a rectangle.
• Lateral Surface Area of cuboid = 2h( l + b )
• Area of Ceiling = lb
• Total Area to be plastered = 2h( l + b ) + lb

Where,

l is length ( 4.5m )

b is breadth ( 3m )

h is height ( 50cm = 0.5m )

Solution:

Area to be plastered-

→ 2h( l + b ) + lb

→ 2 × 0.5( 4.5 + 3 ) + 4.5 × 3

→ 1 × 7.5 + 13.5

→ 7.5 + 13.5

→ 21 m²

Cost of Plastering-

→ Area × Cost per m²

→ 21 × 12

→ Rs 252

_______________

• Henceforth, the cost of plastering is Rs 252