Question

A hemispherical bowl made of brass has inner diameter 10.5 cm. Find the cost of tin-plating it on the inside at the rate of Rs 16 per 100 cm².

`["Assume "pi=22/7]`

 

Answer 1

Inner radius (r) of hemispherical bowl =(10.5/2)cm = 5.25 cm

Surface area of hemispherical bowl = 2πr²

`=[2xx22/7xx(5.25)^2]cm^2`

= 173.25 cm²

Cost of tin-plating 100 cm² area = Rs. 16

Cost of tin-plating 173.25 cm² area`= Rs.(16xx173.25)/100`

= Rs 27.72

Therefore, the cost of tin-plating the inner side of the hemispherical bowl is Rs. 27.72.