Answer:
The cost of plastering the four wall at the rate of Rs 20 per meter square is Rs 3,543.4
Step-by-step explanation:
Given as :
The cost of carpeting a room = Rs 64,000
The rate of carpeting = Rs 540 m²
The breadth is twice its height
The length is twice its breadth
Let The length = L m
The breadth = B m
The height = L m
So, according to question
L = 2 B and B = 2 H
Now, Area of rectangular carpet = Length × Breadth
Or, A = L × B
Or, A = 2 B × B
∵ The cost of carpeting at the rate of Rs 540 per m² = Rs 64,000
So, area = [tex]\frac{64000}{540}[/tex]
Or, 2× B² = 118.518
Or, B² = [tex]\frac{118.518}{2}[/tex]
Or, B² = 59.259
I,.e B = [tex]\sqrt{59.259}[/tex] = 7.69 m
The length = 2 B
I.e L = 2 × 7.69 = 15.38 m
and H = [tex]\frac{B}{2}[/tex]
I.e H = [tex]\frac{7.69}{2}[/tex] = 3.84 m
So, Length = 15.38 m , Breadth = 7.69 m , height = 3.84 m
∵ The area of four wall = 2× ( Length + Breadth ) × height
or, The area of four wall = 2× ( 15.38 + 7.69 ) × 3.84
Or, The area of four wall = 177.17 m²
Now The rate of plastering the four wall = Rs 20 per square meter
So, The cost of plastering the four wall = area of four wall × rs 20
∴ The cost of plastering the four wall = 177.17 × Rs 20
I.e The cost of plastering the four wall = Rs 3,543.4
Hence The cost of plastering the four wall at the rate of Rs 20 per meter square is Rs 3,543.4 answer
