The internal and external diameters of a hollow hemispherical vessel are 24 cm and 25 cm respecttively. If the cost of painting 1 sq.cm of the surface area is Rs. 0.05, find the total cost of painting the vessel all over.
Here is the solution to your question-
external diameter of hollow hemispherical vessel = 25 cm
the external radius R = 25/2 = 12.5 cm
internal diameter of hollow hemispherical vessel = 24 cm
the internal radius r = 24/2 = 12 cm
the surface area of the hollow hemispherical vessel
= curved surface area of the external hemisphere + curved surface area of internal hemisphere+ area of the top
since the cost of the paint 1 sq cm is Rs.0.05/-
therefore the total cost
thus total cost to the nearest rupee to paint the vessel all over is Rs. 96.
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