Question

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

• A. 4.5
• B. 6
• C. 8.5
• D. 5.5

Answer 1

The correct option is D 5.5

The total surface area, $Sc{m}^2$, of a cylinder of radius r cm and height h cm, is given by the formula.
$S=2\pi rh+2\pi r^2$
Also, $S=198$ and
$r=3.5$. (Take $\pi$ to be
$\frac{22}{7}$).
$\therefore$ $198=2\times \frac{22}{7}\times \frac{7}{2}\times h+2\times \frac{22}{7}\times \frac{7}{2}\times \frac{7}{2}$
$\therefore$$h=5.5$