Question

A room is 7 m long, 7 m wide and 3.5 m high. find the cost of covering its walls by a paper of 50 cm wide at the rate of Rs. 1.50 per metre.​

Answer 1

$\sf{\huge{\underline{\red{Given :-}}}}$

• A room is 7 m long, 7 m wide and 3.5 m high.

• A paper of 50 cm wide at the rate of Rs. 1.50 per metre.

$\sf{\huge{\underline{\green{To\:Find :-}}}}$

• The cost of covering its walls .

$\sf{\huge{\underline{\purple{Solution :-}}}}$

We are having,

• Length = 7 m

• Breadth = 7 m

• Hieght = 3.5 m

Area of covering of wall = { Area of 4 walls + Area of the ceiling of the room }

Area of 4 walls = CSA of Cuboid = 2(l+b)h

➝ 2(7+7)3.5

➝ 2 × 14 × 3.5

➝ 28 × 3.5

➝ 98 m²

Area of ceiling of the room = l × b

➝ 7 × 7

➝ 49 m²

Area of covering of wall = { Area of 4 walls + Area of the ceiling of the room }

➝ ( 98 + 49 ) m²

➝ 147 m²

We know, The Cost of covering 1m² of wall with wallpaper is Rs 3.

So, The Cost of covering 147m² of wall with wallpaper

➝ 147× 3

➝Rs 441

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