Question

A water tank is in the shape of a right circular cylinder of internal radius 7 m and height 14
m. It is closed at the top by a hemispherical dome of the same internal radius. The entire inner surface of the tank (including the dome and base) is to be painted with a waterproof coating at the rate of ₹15 per m². What is the total cost of painting the inner surface of the tank? (Take π = 22/7)

Q: Answer-A water tank is in the shape of a right circular cylinder of internal radius 7 m and height 14 m. It...

Inner surfaces to be painted Curved surface of cylinder Inner surface of hemispherical dome Circular base of cylinder Radius r 7 m, height h 14 m Curved surface area of cylinder 2rh 2 227 7 14 2 22 14 616 m Inner surface area of hemisphere 2r 2 227 7 2 227 49 2 22 7 308 m Base area of cylinder r 227 7 227 49 154 m Total area 616 308 154 1,078 m Cost 1,078 15 16,170