What is the simplest way for solving the question of class 9th of exercise 13.4 of math of question no 5 give me the best and simple way for solving this question in simple way of Surface areas and Volumes chapter Give me the best and simple way for solving the question of class 9th of Surface areas and Volumes chapter of math of question no.1 how i solve this question in easy and simple way because it is very important type of question
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A hemispherical bowl made of brass has inner diameter 10.5cm. Find the cost of tin-plating it on the inside at the rate of Rs 16 per 100 cm2. (Assume π = 22/7) Q.5
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Inner radius of hemispherical bowl, say r = diameter/2 = (10.5)/2 cm = 5.25 cm
Formula for Surface area of hemispherical bowl = 2πr2
= 2×(22/7)×(5.25)2 = 173.25
Surface area of hemispherical bowl is 173.25 cm2
Cost of tin-plating 100 cm2 area = Rs 16
Cost of tin-plating 1 cm2 area = Rs 16 /100
Cost of tin-plating 173.25 cm2 area = Rs. (16×173.25)/100 = Rs 27.72
Therefore, the cost of tin-plating the inner side of the hemispherical bowl at the rate of Rs 16 per 100 cm2 is Rs 27.72.