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प्रश्न
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. 4 per 100 `cm^2`
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उत्तर
Given
Inner diameter of hemisphere bowl -10.5cm
Radius - `(10.5)/2`cm - 5.25 cm .
Surface area of hemispherical bowl - 2πr
- 2`[22/7] × (5.25)^2 cm ^2`
-` 173 .25 cm^2`
Cost of tin planning 100`cm^2` area = Rs. 4
Cost of tin planning `173.25 cm^2` area = Rs .`((4 xx173.25)/100)`
= Rs. 6.93
Thus, The cost of tin plating the inner side of hemisphere bowl is Rs .6 93
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