In a temple there are 25 cylindrical pillars. The radius of each pillar is 28 cm and height is 4 m. Find the total cost of painting the curved surface area of pillars at the rate of Rs. 8 per `m^2`. `[ "Take" pi = (22)/(7) ]`

Answer

To find the total cost of painting the curved surface area of 25 cylindrical pillars, we will follow these steps:

### Step 1: Understand the dimensions of the pillars
- The radius of each pillar is given as 28 cm.
- The height of each pillar is given as 4 m.

### Step 2: Convert the radius from centimeters to meters
- Since the height is in meters, we need to convert the radius to meters as well.
- \( \text{Radius in meters} = \frac{28 \text{ cm}}{100} = 0.28 \text{ m} \)

### Step 3: Calculate the curved surface area (CSA) of one pillar
- The formula for the curved surface area of a cylinder is:
\[ \text{CSA} = 2 \pi r h \]
- Substituting the values:
- \( r = 0.28 \text{ m} \)
- \( h = 4 \text{ m} \)
- \( \pi = \frac{22}{7} \)

\[ \text{CSA} = 2 \times \frac{22}{7} \times 0.28 \times 4 \]

### Step 4: Simplify the calculation
- First, calculate \( 2 \times \frac{22}{7} \):
\[ 2 \times \frac{22}{7} = \frac{44}{7} \]
- Now, substitute this back into the CSA formula:
\[ \text{CSA} = \frac{44}{7} \times 0.28 \times 4 \]
- Calculate \( 0.28 \times 4 = 1.12 \):
\[ \text{CSA} = \frac{44}{7} \times 1.12 \]
- Convert \( 1.12 \) to a fraction:
\[ 1.12 = \frac{112}{100} = \frac{28}{25} \]
- Now calculate:
\[ \text{CSA} = \frac{44 \times 28}{7 \times 25} \]
- Simplifying \( \frac{44 \times 28}{175} \):
\[ \text{CSA} = \frac{1232}{175} \approx 7.04 \text{ m}^2 \]

### Step 5: Calculate the total curved surface area for 25 pillars
- Total CSA for 25 pillars:
\[ \text{Total CSA} = 25 \times 7.04 = 176 \text{ m}^2 \]

### Step 6: Calculate the total cost of painting
- The cost of painting is given at Rs. 8 per \( m^2 \).
\[ \text{Total Cost} = 176 \times 8 = 1408 \text{ Rs} \]

### Final Answer
The total cost of painting the curved surface area of the pillars is **Rs. 1408**.

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