Question

The height of a conical tank is 60cm and the diameter of its base is 64 cm, the cost of painting it from outside at the rate of 35 rupees per square meter is

Answer 1

Given:
Height of a conical tank= 60 cm
Diameter of a conical tank= 64 cm
Radius of a conical tank radius of a conical tank= 64/2= 32 cm

Slant height(l) of a conical tank= √r²+h²

l = √ 32² + 60²= √ 1024+3600

= √4624= √17×17×2×2×2×2

= 17×2×2= 68

l= 68 cm

Curved Surface area of a cone= πrl
= (22/7) × 32× 68= 6838.85 cm²

= 6838.85 cm² = 6838.85/10000

= 0.683885 m²

Rate of painting = ₹35 per m²

Cost of painting it from outside = curved surface area of a cone× rate

= 0.683885 × 35 = 23.935975= ₹ 23.94(approx)

Hence, the Cost of painting it from outside = ₹ 23.94(approx)

==================================================================

Hope this will help you....