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A tent is in the shape of a right circular cylinder up to a height of $3$ m and then a right circular cone, with a maximum height of $13.5$ m above the ground. Calculate the cost of painting the inner side of the tent at the rate of ₹2 per square metre, if the radius of the base is $14$ m.
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Height of conical part $= 13.5 - 3 = 10.5$ m
Slant height $= \sqrt{(14)^2 + (10.5)^2} = 17.5$ m
SA of tent = CSA of conical part + CSA of cylindrical part
$= (\frac{22}{7} \times 14 \times 17.5) + (2 \times \frac{22}{7} \times 14 \times 3)$
$= 1034$ m$^2$
Cost of painting @ ₹2 per m$^2 = 1034 \times 2 = 2068$
Slant height $= \sqrt{(14)^2 + (10.5)^2} = 17.5$ m
SA of tent = CSA of conical part + CSA of cylindrical part
$= (\frac{22}{7} \times 14 \times 17.5) + (2 \times \frac{22}{7} \times 14 \times 3)$
$= 1034$ m$^2$
Cost of painting @ ₹2 per m$^2 = 1034 \times 2 = 2068$