# In a building there are 24 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 all pillars at the rate of ₹8 per metre square

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= r = 28cm =0.28m

height ,h=4m

curved surface area of a cylinder =2πrh

curved surface area of a pillar= 2×22\6×0.28×4=7.04metresq.

Curved surface area of 24 such pillars = 7.04×24=168.96metresq.

cost of cementing an area of 1metresq. =Rs8

so,cost of painting 1689.6metresq.=168.96×8=Rs1,351.68

h =4m

area of curved surface =2rh =7.04m

cost per m square = 8

cost for 7.04m = 7.04 x 8 =56.32m square x 24 = 1359.36