Question

in a building there are 24 cylindrical pillars . the radius of each pillar is 28cm and height is 4m. find the total cost of pointing the curved surface area of all pillars at the rate of Rs.8 per meter 2.​

Answer 1

Answer:

The radius of each pillar is 28 cm and height is 4 m. Find the total cost of painting the curved surface area of all pillars at the rate of ₹8 per metre square. 2. See answers.

Answer 2

★ Answer ★

${ \bold { \underline{\large\pink{Correct \: Question : - }}}} \:$

In a building there are 24 cylindrical pillars. The radius of each pillar is 28 cm and height is 7m. Find the total cost of painting the curved surface area of all pillars at the rate of Rs.8 per m².

${ \bold { \underline{\large\pink{Given : - }}}} \:$

★ Radius of pillar = 28cm

Converting in m.

= 0.28m

★ Height of pillar = 7m

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${ \bold { \underline{\large\pink{To \: Find : - }}}} \:$

★ Total cost of painting the curved surface area of all pillars at the rate of Rs.8 per m².

⠀

${ \bold { \underline{\large\pink{Solution : - }}}} \:$

Step by step explanation:-

As we all know that the pillar is in cylindrical shape.

So, Now applying the Curved surface area of cylinder

Curved surface area of cylinder = 2πrh

★ Using Formula

C.S.A of a cylinder = 2πrh

By Substituting the values in the above formula, we get

⠀

C.S.A of a pillar = 2 × 22/7 × 0.28 × 7

$\longmapsto\tt{CSA =2\times\dfrac{22}{{\cancel{7}}}\times{0.28}\times{{\cancel{7}}}}$

⠀⠀⠀⠀⠀⠀⠀⠀⠀ = 12.32m²

C.S.A of 24 such pillar = 12.32× 24

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀ = 295.68m²

Cost of painting an area of 1m² = Rs.8

Therefore,

Cost of painting 295.68m² = 295.68 × 8

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀= Rs.2365.44

Hence,

➤ Cost of painting 24 pillars ↬ 2365.44Rs.

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