Question

The cost of painting a conical tent of radius $3.5m$ and slant height $7m$ at a rate of $₹10/m^2$ is .

• A. $₹770$
• B. $₹335$
• C. $₹1,005$
• D. $₹370$

Answer 1

The correct option is A $₹770$

Given that,
radius of cone is $3.5m$.
Slant height of cone is $7m$.
Rate of painting is $₹10/m^2$.

We know that,
curved surface area of a cone $=\pi rl$

Now, cost of painting the tent
$=\text{Rate of painting}\times \text{Curved surface area of tent}$
$=10\times \frac{22}{7}\times \frac{35}{10}\times 7$
$=₹770$