Question

A dome of a building is in the form of a hemisphere from inside it was White wash at the cost of rupees £4.98. 96 if the cost of whitewashing is @ rupees 2 per square metre find the inner surface area of the Dome

Answer 1

(i) Cost of white-washing the dome from inside = Rs 498.96

Cost of white-washing 1 m2 area = Rs 2

Therefore, CSA of the inner side of dome =

= 249.48 m2

(ii) Let the inner radius of the hemispherical dome be r.

CSA of inner side of dome = 249.48 m2

2πr2 = 249.48 m2



⇒ r = 6.3 m

Volume of air inside the dome = Volume of hemispherical dome



= 523.908 m3

= 523.9 m3 (approximately)

Therefore, the volume of air inside the dome is 523.9