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 the curved surface area of all pillars at the rate of Rs. 8 per meter square

Answer 1

C.S.A. of cylindrical =2πrh

⇒ C.S.A. of are pillar =2× 7/22 ×28×4=704cm²

⇒ C.S.A. of 24 pillars =24×704=16896cm²

=16896×10^−4m²

=1.69m²

Therefore,

Total cost= Rs. 8×1.69

= Rs.13.52

Answer 2

Answer:

Rs.1351.68

Step-by-Explanation:

Radius of each Pillar=28cm=0.28m

Height of each pillar=4m

CSA of 1 pillar=2πrh

= 2 x 22

--------- x 0.28 x 4

7

49.28

= --------

7

= 7.04 m2

Area of Pillars = 7.04(24) = 168.96cm2

Cost Of Painting per m2 = Rs.8

Total Cost = Rs.8 x 168.96 = 1351.68

Hope it helps!

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