Question

The diameter of base of a chimney of kiln is 80 cm and height is 12.5 m. What will be the cost of painting this chimney from outside at the rate of Rs. 140 per sq m?

Answer 1

Solution :-

Given: diameter of base of chimney $=80cm=0.8m$

Height of chimney $=12.5m$

curved surface are $=2\pi rh$ $=2\times \frac{22}{7}\times 0.4\times 12.5$$=31.42m^2$

cost of painting $1$ sq m $=Rs140$

$\therefore$ Total cost $=31.42\times 140$

$Rs=4398.8$