The slant height and base diameter of a conical tomb are 25 m and 14 m respectively. Find the cost of white-washing its curved surface at the rate of Rs. 210 per 100 \({m}^2\).

Given :
Slant height (l) of conical tomb = 25 m
Base radius (r) of tomb = \(\frac{14}{2} = 7 m\)

We know, CSA of tent = \({\pi}rl\)
= [\(\frac{22}{7} × 7 × 25 m\)]
= [\(22 × 1 × 25 m\)]
= \(550 {m}^2\)

Now, we know that,
Cost of white-washing 100 \({m}^2\) area = Rs. 210
So, Cost of white-washing 550 \({m}^2\) area
= Rs. [\(\frac{210 × 550}{100}\)]
= Rs. 1155

Therefore, it will cost of Rs. 1155 while white-washing such a conical tomb.