Question

A hemispherical bowl made of brass has inner diameter 10.5 cm. Find the cost of the plating it on the inside at the rate of Rs. 4 per 100 cm².

Answer 1

Surface area of a hemisphere = 2πr² 

Given, 

diameter of the hemisphere bowl is 10.5 cm 

Surface area of the bowl = 2 × (22/7) × (10.5/2)2 = 173.25 cm² 

Given, 

cost of the plating it on the inside at the rate of Rs. 4 per 100 cm²

Cost of plating the hemisphere bowl = \(\frac{4}{100}\times\) 173.25 

= Rs. 6.93