Question

the length,breadth and height of a room are 5m,4m and3m respectively.find the cost of white washing the walls of the room and the ceiling at the rate of 7.50per m​

Answer 1

Given :-

Length of the room = 5 m

Breadth of the room = 4 m

Height of the room = 3 m

Rate of whitewashing per meter = Rs. 7.50

To Find :-

Total area to be white washed.

Cost of white washing the walls of the room and the ceiling.

Analysis :-

Total area to be white washed = Area of walls + Area of ceiling of room

Multiply the total area to be white washed by the rate of whitewashing per meter.

Solution :-

We know that,

• l = Length
• b = Breadth
• h = Height
• a = Area

Four walls and the ceiling of the room are to be white washed.

According to the question,

Total area to be white washed = Area of walls + Area of ceiling of room

Substituting their formula,

$\underline{\boxed{\sf 2lh+2bh+lb}}$

By substituting,

= 2 × 5 × 3 + 2 × 4 × 3 + 5 × 4

= 30 + 24 + 20

= 74

Therefore, the area is 74 m²

Now,

Given that, rate of whitewashing per meter = Rs. 7.50

Cost of white washing 74 m² area = 74 × 7.50

Cost of whitewashing = Rs. 555

Therefore, the cost of whitewashing is Rs. 555