Question

Calculate the value of $h$, when $S=198$ and $r=3.5$ (Take $\pi$ to be $\frac{22}{7})$.

• A. $2.5$
• B. $5.5$
• C. $7.2$
• D. $9$

Answer 1

The correct option is B $5.5$

Given, $S=198,r=3.5$
Since, Total surface area of cylinder $\left(S\right)=2\pi rh+2\pi r^2$
$\Rightarrow 198=2\pi r(h+r)$
$\Rightarrow 198=2\times \frac{22}{7}\times 3.5(h+3.5)$
$\Rightarrow 198=2\times \frac{22}{7}\times \frac{35}{10}(h+3.5)$
$\Rightarrow 198=22(h+3.5)$
$\Rightarrow \frac{198}{22}=h+3.5$
$\Rightarrow 9=h+3.5$
$\Rightarrow h=9-3.5=5.5$