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 m².

Radius of conical tomb r = 14/2 = 7 m and slant height l = 25 m
Curved surface area of conical tomb = πrl
= 22/7 × 7 × 25 = 550 m²
Cost of white washing at the rate of Rs 210 per 100 m² = Rs 550 × 210/100 = Rs. 1155
Hence, the cost of white washing curved surface area is Rs 1155.