a tent of shape of a right circular cylinder upto a height of 3m and then becomes a right circular conewith height of 13.5m above the ground calculate the cost of painting the inner side of the text at the rate of RS 2 PER Sq m if radius of the base is 14m

Let *r* m be the radius of cylindrical base of cylinder of height *h*_{1 }m.

∴ *r* = 14 m and *h*_{1} = 3 m

Curved surface area of cylinder = 2 π*rh*_{1} m^{2}

The radius of cylindrical base of cylinder is also equal to the radius of right circular cone.

Let *h*_{2} be the height of cone and *l* be the slant height of cone.

*r* = 14 m and *h*_{2} = (13.5 - 3) m = 10.5 m

*l*^{2} = *r*^{2} + *h*_{2}^{2}

*l*^{2} = (14)^{2} + (10.5)^{2}

∴ Curved surface area of the cone = π*rl*

∴ Total area of tent which is to be painted

= Curved surface area of cylinder + Curved surface area of cone

= (264 + 770) m^{2}

= 1034 m^{2}

Now, Cost of painting 1 m^{2} of inner side of tent = Rs 2

∴ Cost of painting 1034 m^{2} inner side of tent = Rs 2 × 1034 = Rs 2068

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