Question

It costs Rs 2200 to paint the inner curved surface of a cylindrical vessel 10 m deep. If the cost of painting is at the rate of Rs 20 per m², find 

(i) Inner curved surface area of the vessel, 

(ii) radius of the base, 

(iii) capacity of the vessel.

Answer 1

Here, h = 10 m 

(i) Inner curved surface area = Total cost / Cost of painting per m² 

= 2200 / 20 m² = 110 m² Ans. 

(ii) We have, 2πrh = 110 

⇒ 2 × 22 / 7 × r × 10 = 110 

⇒ r = 110 x 7/ 2 x 22 x 10 = 1.75 m Ans. 

(iii) Capacity of the vessel = π r²h 

= 22/ 7 × 1.75 × 1.75 × 10 m³ = 96.25 m³ 

= 96.25 kl Ans. [1 m³ = 1 kl]