Question

A cuboidal box has length, breadth and height as 20cm, 10cm and 5cm respectively. The box has to be
covered completely with a red coloured paper. How many sheets of square shaped red colour paper of side
10cm will be required?

Answer 1

Given:-

• Length of Cuboidal box = 20 cm

• Breadth of Cuboidal box = 10 cm

• Height of Cuboidal box = 5 cm

• Side of the red Square sheet = 10 cm

• Box has to be covered completely with a red coloured paper.

To Find:-

• No. of sheets of square shaped red colour paper of side 10cm will be required to cover the box completely.

Formula Used:-

• ${\boxed{TSA\:of\: Cuboid=2(lb + bh + hl)}}$

• ${\boxed{TSA\:of\: Square=Side^2}}$

Solution:-

Firstly,

$\sf :\implies\:TSA\:of\: Cuboid=2(lb + bh + hl)$

$\sf :\implies\:TSA\:of\: Cuboid=2(20\times10 + 10\times5 + 5\times20)$

$\sf :\implies\:TSA\:of\: Cuboid=2(200 + 50 + 100)$

$\sf :\implies\:TSA\:of\: Cuboid=2\times350$

${\boxed{\sf{:\implies\:TSA\:of\: Cuboid=700cm^2}}}$

Now,

$\sf :\implies\:TSA\:of\: Square \:sheet=Side^2$

$\sf :\implies\:TSA\:of\: Square \:sheet=10^2$

$\sf :\implies\:TSA\:of\: Square \:sheet=100cm^2$

$\sf No. \:of \:Sheets \:required =\dfrac{Surface\:Area\:of\:Box}{Surface\:Area\:of\:one\:Sheet}$

$\sf No. \:of \:Sheets \:required =\dfrac{700}{100}$

${\boxed{\sf{No. \:of \:Sheets \:required =7}}}$

Hence, 7 sheets of square shaped red colour paper of side 10cm will be required to cover the box completely.

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Answer 2

Answer:

7

Step-by-step explanation:

TSAofCuboid=2(lb+bh+hl)

\sf :\implies\:TSA\:of\: Cuboid=2(20\times10 + 10\times5 + 5\times20):⟹TSAofCuboid=2(20×10+10×5+5×20)

\sf :\implies\:TSA\:of\: Cuboid=2(200 + 50 + 100):⟹TSAofCuboid=2(200+50+100)

\sf :\implies\:TSA\:of\: Cuboid=2\times350:⟹TSAofCuboid=2×350

{\boxed{\sf{:\implies\:TSA\:of\: Cuboid=700cm^2}}}

:⟹TSAofCuboid=700cm

2

Now,

\sf :\implies\:TSA\:of\: Square \:sheet=Side^2:⟹TSAofSquaresheet=Side

2

\sf :\implies\:TSA\:of\: Square \:sheet=10^2:⟹TSAofSquaresheet=10

2

\sf :\implies\:TSA\:of\: Square \:sheet=100cm^2:⟹TSAofSquaresheet=100cm

2

\sf No. \:of \:Sheets \:required =\dfrac{Surface\:Area\:of\:Box}{Surface\:Area\:of\:one\:Sheet}No.ofSheetsrequired=

SurfaceAreaofoneSheet

SurfaceAreaofBox

\sf No. \:of \:Sheets \:required =\dfrac{700}{100}No.ofSheetsrequired=

100

700

{\boxed{\sf{No. \:of \:Sheets \:required =7}}}

No.ofSheetsrequired=7