हिंदी

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 ₹ 16 per 100 cm2. Assume [Assume π=227]

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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 ₹ 16 per 100 cm2.

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

योग
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उत्तर

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 = ₹ 16

Cost of tin-plating 173.25 cm2 area = `₹ (16 xx 173.25)/100`

= ₹ 27.72

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

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अध्याय 11: Surface Area and Volumes - EXERCISE 11.2 [पृष्ठ १४५]

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एनसीईआरटी Mathematics [English] Class 9
अध्याय 11 Surface Area and Volumes
EXERCISE 11.2 | Q 5. | पृष्ठ १४५

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