Question

A cyclindrical hole of diameter 30 cm is bored through a cuboid
wooden block with side 1 metre. Find the volume of the object so
formed.​

Answer 1

Answer: Volume of the object = Volume of the cuboid − Volume of the cylinder

Volume of a cuboid of length l, breadth b and height h =l×b×h.

As, all the sides of the cuboid are equal, volume of the cuboid =1m×1m×1m=1m  

3

=1000000cm  

3

 

Volume of a Cylinder of Radius "R" and height "h" =πR  

2

h

The Radius of the given cylinder is  

2

30

​  

=15cm and its height is 1m=100cm

Hence, volume of the given cylinder =3.14×15×15×100=70650cm  

3

 

Hence, volume of the object =1000000−70650=0.9292857m  

3

=929350cm  

3

Answer 2

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

• A cyclindrical hole of diameter 30 cm is bored through a cuboid wooden block with side 1 metre.

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

• The volume of the object.

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

A cylindrical hole of diameter 30 cm.

➝ The radius will be = 30/2 = 15 cm

The wooden cuboidal block have side 1m.

= 100 cm each ,

Hence, all sides equal so its a cube .

• So, The volume of the block

➝ a³

➝ 100 × 100 × 100

➝ 1000000 cm²

• The volume of cylindrical hole

➝ π r² h

➝ 3.14 × 15 × 15 × 100

➝ 3.14 × 225 × 100

➝ 315 × 225

➝ 70650 cm²

The volume of the object = ( The volume of the block - The volume of cylindrical hole )

➝ 1000000 - 70650

➝ 929350 cm²

The volume of the object is 929350 cm².

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