Find the cost of painting 15 cylindrical pillars of a building at Rs. 2.50 per square metre if the diameter and height of each pillar are 48 cm and 7 metres respectively.
It is given in the question that,
Diameter of the cylindrical pillars = 48 cm
Hence,
The radius of the cylindrical pillars =
= 24 cm
= 0.24 m
Height of the cylindrical pillars = 7 m
Now,
Lateral surface area of one pillar = 
= 
= 10.56 m2
Now,
The surface area to be painted = total surface area of 15 pillars
= 15 × 10.56
= 158.4 m2
Therefore,
The total cost of painting = Rs(158.4 × 2.5)
= Rs 396
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