Question

The formula for the volume of a cylinder is $V=\pi r^{2}h$, where $\pi =\frac{22}{7}$

Find $h$, when $V=770$ and $r=3.5$

• A. $20$
• B. $45$
• C. $34$
• D. $23$

Answer 1

The correct option is A $20$

Given, Volume(V) $=770,Radius\left(r\right)=3.5$
Since, Volume of cylinder $=\pi r^{2}h$
$\Rightarrow 770=\frac{22}{7}\times (3.5{)}^{2}h$
$\Rightarrow 770=\frac{22}{7}\times \left(3.5\right)\times 3.5h$
$\Rightarrow \frac{770\times 7}{22\times 3.5\times 3.5}=h$
$\Rightarrow \frac{770\times 7\times 10\times 10}{22\times 35\times 35}=h$
$\Rightarrow h=20$
Hence, option A is correct.