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A bucket made of aluminium sheet is of height 20 cm and its upper and lower ends are of radius 25 cm and 10 cm respectively. Find the cost of making the bucket if the aluminium sheet costs Rs. 70 per 100 cm3 (use π = 3.14) |
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Answer» Slant height, l = \(\sqrt{(r' - r")^2 + h^2}\) ⇒ l = \(\sqrt{(25- 10)^2 + 20^2}\) ⇒ l = 25 cm ∴ Slant height of the bucket, l = 25 cm Curved surface area = π(r’ + r’’)l + πr’’2 = π(25 + 10)(25) + π (10)2 = 3061.5 cm2 Cost of making bucket per 100 cm2 = Rs 70 Cost of making bucket per 3061.5 cm2 = \(\frac{3061.5}{100}\times70\) = Rs 2143.05 ∴ Total cost = Rs 2143.05 |
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