Question

In a building there are 24 cylindrical pillars with each having a radius 28 cm and height 4 m. Find the cost of painting at a rates of 8 rupees per meter.
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Answer 1

Answer:

The cost of painting the curved surface area of 24 hours at the rate of ₹ 8 per m² is ₹ 1351.68.

Step-by-step explanation:

Given:

• No of cylindrical pillars in a building = 24
• The radius of each pillar = 28cm
• Height of each pillar = 4m

Need to find:

• The cost of painting the curved surface area of 24 hours at the rate of ₹ 8 per m²

Explanation:

As it given that,

Radius of cylindrical pillar = 28cm = 0.28m

Height of the cylindrical pillar = 4m

As we know that,

Curved surface area of a cylinder = 2πrh

Putting values in this formula,

We get:

=> 2×22/7×0.28×4

=> 7.04m²

Therefore,

Curved surface area of 24 such pillars = 7.04×24

=> 1689.96m²

As it given that,

Cost of painting an area of 1m² = ₹ 8

Therefore,

Cost of painting 1689.6m² = 168.96×8

=> ₹ 1351.68

Hence,The cost of painting the curved surface area of 24 hours at the rate of ₹ 8 per m² is ₹ 1351.68.

Answer 2

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AnswEr:

• The cost of painting at a rates of 8 rupees per meter = Rs. 1351.68.

Given:

• Height of each pillar = 4 cm
• Radius of each pillar = 28 cm = 28/100m

Need To Find:

• Cost of painting the pillars = ?

We find curved surface area (CSA)of pillars.

Curved surface area of pillar

Formula used here:

• Curved surface area = 2πrh

= 2 × 22/7 × 28/100 × 4

= 2 × 22 × 4/100 × 4

= 44 × 16 × 1/100

= 704/100m²

Now there are 24 Pillars.

So,

Total surface area to be painted

= 24 × Curved surface area of 1 pillar

= 24 × 704/100

= 16896/100

= 168.96 m²

Now,

Cost of painting is Rs 8 per m²

So,

Cost of painting per 1m² = Rs 8

Cost of painting per 168.96m² = Rs 8 × 168.96

= Rs 8 × 16896/100

= Rs 135168/100

= Rs. 1351.68

• Hence,the cost of painting at a rates of 8 rupees per meter is Rs. 1351.68.

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