Question
Download Solution PDFA hemispherical bowl made of iron has inner diameter 84 cm. Find the cost of tin plating it on the inside at the rate of Rs. 21 per 100 cm2 (take \(\pi = \frac{{22}}{7}\)) correct to two places of decimal.
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFGiven:
Inner Diameter = 84 cm
Cost of tin plating it on the inside = Rs. 21 per cm2.
Concept Used:
Curved Surface area of Hemisphere = 2π r2
Calculation:
Inner Diameter = 84 cm
Inner Radius = 84/2 cm = 42 cm
Curved Surface area of Hemisphere = 2π r2
⇒ 2 × 22/7 × 422
⇒ 2 × 22 × 6 × 42
⇒ 11088 cm2
The cost of tin-plating 100 cm2 of the bowl = Rs. 21
The cost of tin-plating 1 cm2 of the bowl = Rs. 21/100
The cost of tin-plating 11088 cm2 area of the bowl = (21/100) × 11088 = Rs. 2,328.48
Thus, the cost of tin-plating is Rs. 2,328.48.
∴ Option 1 is the correct answer.
Last updated on Jul 19, 2025
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