Question

the walls and ceiling of a room are to be plasted. the length and breadth and height of a room are 5,4,3 cm . find the cost of plastering at the rate of 10 per m square

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

Answer 2

Answer :

• Rs.840 is the cost of plastering at the rate of 10 per m square

Given :

• The walls and celling of a room to be pasted
• The length, breadth and height of a room are 5m,4m and 3m

To find :

• The cost of plastering at the rate of 10 per m square

Solution :

Given,

• Length of room = 5m
• Breadth of room = 4m
• Height of room = 3m

As we know that,

• Area of celling = length × breadth

》5 × 4

》20m²

Hence, Area of celling is 20m²

As we know that,

• Area of walls = 2(lb + bh) m²

》2((5)(4) + (4)(3)) m²

》2(20 + 12) m²

》2(32) m²

》64m²

Hence, Area of walls is 64m²

Now we have to find the sum of area of cellings and walls :

》20m² + 64m²

》84m²

Now Given that,

• Cost of plastering at the rate of 10 per m square so,

》Cost of plastering 1m² area = Rs.10

》Cost of plastering 84m² area = 84 × 10 = 840 Rs

Hence , Rs.840 is the cost of plastering at the rate of 10 per m square