Question

Pavan has built a conical flask using $550m^2$ of aluminium sheet. If the radius of the flask is $7m,$ then how much water he can fill into the flask (in litres)?

[The bottom of flask is made out of some other material]

• A. 1232
• B. 1232000
• C. 123200
• D. 1.232

Answer 1

The correct option is B

1232000

Since, the area of aluminium sheet $=$ Curved surface area of flask
$\Rightarrow 550m^2=\pi rl=\frac{22}{7}\times 7\times l$

$\Rightarrow l=\frac{550}{22}=25m$

$\Rightarrow h=\sqrt{l^2-r^2}$

$\Rightarrow h=\sqrt{{25}^2-7^2}$

$\Rightarrow h=24m$

Volume of conical flask $=\frac{1}{3}$ $\pi$$r^{2}h$

$=\frac{1}{3}\times \frac{22}{7}\times 7^2\times \sqrt{176}$

$=1232m^3$

We know that $1m^3=1000l$

So, volume in litres $=1232000l$