Question

The internal measures of the length , breadth and height of a room are 12 m , 8
m and 4 m respectively. Find the cost of whitewashing all four walls of the room ,
if the cost of white washing is ₹ 5 per sq. m.
​

Answer 1

Answer:

The total cost is Rs. 1280.

Step-by-step explanation:

Length = 12m

Breadth = 8m

Height = 4m

Rate = ₹ 5 per sq. m

★ Lateral surface area = 2(l + b)h

⇒ 2(12+8)4

⇒ 8 × 20

⇒ 160 sq m.

★ Cost = Rs. 5 per sq m

⇒ 160 × 5

⇒ Rs. 800

★ Area of ceiling = Length × Breadth

⇒ 12 × 8

⇒ 96 sq m

★ Cost = 5 × 96

⇒ Rs. 480

★ Total cost = 800 + 480

⇒ Rs. 1280

Therefore, the total cost is Rs. 1280.

Answer 2

Answer:

rs.1280

Step-by-step explanation:

Dimensions = 12m * 8m * 4m

Lateral surface area = 2(l+b) h

= 2(12+8)4 = 8*20= 160 sq m

Cost rs. 5 per sq m

Total cost = 160* 5 = rs. 800

Area of ceiling = 12*8 = 96 sq m

So, cost = rs 5 * 96

= rs. 480

Total cost = 800+480

=rs.1280