Question

The cost of carpeting a square room at Rs 25

per square metre is Rs 8100. It has a door of
1m*2m and a window 3m*1m. The height of
aroom is 6 m find the area of four walls of
the room excluding the door and window

Answer 1

The area of the four walls of the room, excluding the door and window, is 427 square meters. The calculation involves finding the perimeter of the room, multiplying by its height, and then subtracting the areas of the door and window.

• The student is asking how to calculate the area of the four walls of a square room by excluding the area of a door and a window.
• The cost of carpeting the room at a rate of Rs 25 per square meter is Rs 8100, which indicates that the area of the carpeted floor is 8100 / 25 = 324 square meters.
• Since this is a square room, each side of the room has a length of the square root of 324, which is 18 meters.
• The area of the walls can be found by multiplying the perimeter of the room by the height of the room.
• The perimeter is 4 times the length of the side, so that's 4 * 18 = 72 meters.
• Multiplying this by the height of the room (6 meters), we get 72 * 6 = 432 square meters for all four walls together.
• To find the area of the four walls excluding the door and window, we subtract the area of the door (1m * 2m = 2m²) and the area of the window (3m * 1m = 3m²) from the total area of the walls.
• This gives us 432m² - 2m² - 3m² = 427m² as the final area of the four walls excluding the door and window.

Answer 2

Answer: Areas = 139m²

Cost = Rs3475

Explanation:

Area of a square wall of xm= xm².The area of the 4 walls = 4x²m²

Therefore, since the height = 6m, the other side = 6m, the area = 6x6=36m².

Area of the Four walls = 36m²x 4

= 144m². Biu the areas of the four walls excluding the door and window. Area of the door = 2m x 1m= 2m², and area of the window = 3m x 1m = 3m². Total area of the door and window = 2m² + 3m² = 5m².

Therefore, the total area of the four walls excluding the door and window = 144m² - 5m²

= 139m².

The amount required to carpeting the room will be

Let the number of square room carpeted at Rs25 which equals Rs8100 = xm²

Therefore, to know the number of square covered by this amount,= Rs8100/Rs25 = 324m²

If 324m² = Rs8100

1m² = 8100/324

139m²= 8100/324 x 139

= Rs3475