Question

The cost of carpeting the floor of a room, whose breadth is twice it’s height and length is twice it’s breadth, at the rate of Rs.540 m² is Rs. 64,000. What will be the cost of plastering its 4 walls at the rate of Rs 20 per square meter.

Answer 1

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  = $\frac{64000}{540}$

Or, 2× B² = 118.518

Or,      B² = $\frac{118.518}{2}$

Or,      B² = 59.259

I,.e      B  = $\sqrt{59.259}$ = 7.69 m

The length = 2 B

I.e   L = 2 × 7.69 = 15.38 m

and  H = $\frac{B}{2}$

I.e    H =  $\frac{7.69}{2}$ = 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