Question

Find the height of a cylinder whose radius is 7 m and total surface area is 968 $m^2$.

• A. 7 m
• B. 9 m
• C. 10 m
• D. 11 m

Answer 1

The correct option is A

7 m

Total surface area of a cylinder = $2\pi r^2+2\pi rh$

r = 7 m, TSA = 968 $m^2$

Let the height of the cylinder be h

$\Rightarrow$ 968 = 2 x $\frac{22}{7}$ x 7 x 7 + 2 x $\frac{22}{7}$ x 7 x h

$\Rightarrow$ 968 = 308 + 44h

$\Rightarrow$ h = $\frac{968-308}{44}$ = $\frac{660}{44}$ = 15 m