Question

A classroom is 30ft long 20ft wide and 12 ft high .find the cost of stitching the wallpaper on 4walls and ceiling at Rs 120\sq.ft
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Answer 1

$\large\underline{\sf{Solution-}}$

Given that,

Length of the room, l = 30 ft

Breadth of the room, b = 20 ft

Height of the room, h = 12 ft

Now, We have to find the area of stitching the wall paper on 4 walls and ceiling.

So, Required area of stitching the wall paper is

$\rm \: = \: Area_{(Four\:walls)} \: + \: Area_{(ceiling)}$

$\rm \: = \: 2(l + b) \times h + lb$

$\rm \: = \: 2(30+ 20) \times 12 + 30 \times 20$

$\rm \: = \: 2(50) \times 12 + 600$

$\rm \: = \: 100 \times 12 + 600$

$\rm \: = \: 1200 + 600$

$\rm \: = \: 1800 \: {ft}^{2}$

Further, given that

Cost of stitching wall paper 1 sq. ft = Rs 120

So,

Cost of stitching wall paper 1800 sq. ft = Rs 120 × 1800 = Rs 216000

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ADDITIONAL INFORMATION

Formulas of Cube :-

Total Surface Area = 6(side)²

Curved Surface Area = 4(side)²

Volume of Cube = (side)³

Diagonal of a cube = √3(side)

Perimeter of cube = 12 x side

Formulas of Cuboid

Total Surface area = 2 (Length x Breadth + breadth x height + Length x height)

Curved Surface area = 2 height(length + breadth)

Volume of the cuboid = (length × breadth × height)

lDiagonal of the cuboid =√(l² + b² + h²)

Perimeter of cuboid = 4 (length + breadth + height)

Answer 2

Solution:

Length of the room = 30ft

Breath of the room = 20ft

Height of the room = 12ft

Now,

$\implies \rm \: area_{(four \: \: walls)} + \: area_{(cieling)}$

= 2(l+b) × h + lb

= 2 (30+20) × 12 + 30 × 20

= 2(50) × 12 + 600

= 100 × 12 + 600

= 1200 + 600

= 1800ft²

Hence, cost of stitching wall paper 1sq. ft =Rs120

So,

Cost of stitching wallpaper 1800 sq. ft

= Rs 120×1800

=> Rs 216000