Question

A tent is of the shape of a right circular cylinder upto a height of 3 metres and then becomes a right circular cone with a maximum height of 13.5 metres above the ground. Calculate the cost of painting the inner side of the tent at the rate of Rs 2 per square metre, if the radius of the base is 14 metres.

Answer 1

Let r m be the radius of cylindrical base of cylinder of height by m

r = 14 m and h₁ = 3m

Curved surface area of cylinder

The radius of cylindrical box of cylinder is also equal to the radius of right circular cons.

Let h₂ be the height of cone and l be the slant height of cone

Curved surface area of the cone

Curved surface of area of cone

Therefore,

Total area of tent which is to be painted

= curved surface area of cylinder + curved surface area of cone

Now cost of painting 1 m² of inner side of tent = Rs. 2

Cost of painting 1034 m² inner side of tent