Question
A cylindrical vessel, without lid, has to be tin coated including both of its sides. If the radius of its base is 1/2 m and its height is 1.4 m, calculate the cost of tin-coating at the rate of Rs. 50 per 1000 cm2.
Solution
Radius of the base (r) =
m
= .png)
× 100 cm = 50 cm
Height (h) = 1.4 m
= 1.4 × 100 cm
= 140 cm.
Surface area of to tin-coated = 2 (
)
= 2[2 × 3.14 × 50 × 140 + 3.14 × (50)2]
= 2[43960 + 7850] = 2(51810) = 103620 cm2
∴ Cost of tin-coating at the rate or Rs. 50 per 1000 cm2
= 
× 103620 = Rs 5181. Ans.
