Question

A right circular cone with diameter as 14 m and slant height as
12 m. Determine the cost of colouring its total surface at the
rate of 14 Rs per sq. m.
A: 144
B: 213
C: 325
D: 418​

Answer 1

Given:-

• A right circular cone with diameter as 14 m and slant height as 12 m.

To Find:-

• Cost of colouring its total surface at the rate of Rs. 14 per m².

Formula Used:-

• ${\boxed{\bf{Radius=\dfrac{Diameter}{2}}}}$

• ${\boxed{\bf{TSA\:of\: Cone=\pi r(l+r)}}}$

Solution:-

Firstly,

$\sf :\implies\:Radius=\dfrac{Diameter}{2}$

$\sf :\implies\:Radius=\dfrac{14}{2}$

$\bf :\implies\:Radius=7\:m$

Now,

$\sf :\implies\:TSA\:of\: Cone=\pi r(l+r)$

$\sf :\implies\:TSA\:of\: Cone=\dfrac{22}{7}\times 7(12+7)$

$\sf :\implies\:TSA\:of\: Cone=22\times19$

$\bf :\implies\:TSA\:of\: Cone=418\:m^2$

Cost of colouring its total surface at the rate of Rs. 14 per m²:-

$\sf :\implies\:418\times14$

$\sf :\implies\:Rs. \:5,852$

Hence The Cost of colouring its total surface at the rate of Rs. 14 per m² is Rs. 5,582.

━━━━━━━━━━━━━━━━━━