Question

22. A water tank of cylindrical 3 po
shape has diameter 1m and
height 2m .Tank is closed with
lid.The tank is to be painted
internally and externally
including the lid .Find the area
of the surface to be painted. *​

Answer 1

Correct Question:-

• A water tank of cylindrical shape has diameter 1 m and height 2 m. Tank is closed with lid. The tank is to be painted internally and externally including the lid.Find the expenditure if the rate of painting is ₹ 80 per sqm. ( π = 3.14)

Given:-

• radius of cylindrical tank , r = 1/2 = 0.5 m
• height of cylindrical tank , h = 2m

step-by-step solution:-

so, surface are of tank = 2πrh

⟶ 2 × 3.14 × 0.5 × 2

⟶ 6.28 m²

a/c to question,

tank is closed with lid.

so, surface area of lid = 2πr²

⟶ 2 × 3.14 × 0.5 × 0.5

⟶ 3.14 × 0.5 = 1.57 m²

hence, total surface area = 1.57 + 6.28 = 7.85 m²

because the tank is to be painted internally and externally including the lid , total area to be painted = 2 × area of tank

⟶ 2 × 7.85 = 15.7m²

now, expenditure = total area × rate of painting

⟶ 15.7 × 80 = 1256

hence, answer is ₹ 1256