Math, asked by shubhajit94, 4 months ago

is
8.
The length of a roller is 40 cm and its diameter is 21 cm. It takes 300 complete
revolutions to move once over to level the floor of a room. Find the area of the
room in m2.​

Answers

Answered by cutiepie3234
3

is

8.

The length of a roller is 40 cm and its diameter is 21 cm. It takes 300 complete

revolutions to move once over to level the floor of a room. Find the area of the

room in m2.

Answered by itscandycrush
23

Answer:-

Given:-

  • Length of roller = 40cm

  • Diameter of Roller = 21 cm

  • Number of times revolution taken to level the floor of the room = 300

To Find:-

  • Area of Room in m²

Formula Used:-

  • Radius = Diameter ÷ 2

  • Lateral Surface area of Cylinder = 2 × π × radius × height

Concept Used:-

  • Area of room = No. of revolution × L.S.A. of Roller

Solution:-

Finding Radius of roller

Radius

= Diameter ÷ 2

= 21 ÷ 2

= 10.5 cm

∴ Radius of roller = 10.5 cm

Finding L.S.A. of roller

Lateral Surface area of Cylinder

= 2 × π × radius × height

= 2 × π × 10.5 × 40

= 2 × (22/7) × 10.5 × 40

= 2 × 22 × 1.5 × 40

= 44 × 60

= 2640cm²

∴ L.S.A. of roller = 2640 cm²

Finding area of room

Area of room

= 300 × L.S.A. of Roller

= 300 × 2640

= 792000 cm²

Area of room in m²

= 792000cm²

= 792000 ÷ 10000 [1m² = 10000cm²]

= 79.2 m²

∴ Area of room in m² = 79.2 m²

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