Question

Find the height of a cylinder whose radius is $10cm$ and the total surface area is $2420c{m}^2$.

• A. $28.5cm$
• B. $285cm$
• C. $56.5cm$
• D. None of these

Answer 1

Answer: (A)

$28.5cm$

TSA of cylinder = $2\pi r(r+h)$

$\Rightarrow 2420{cm}^2=2\times \frac{22}{7}\times 10(10+h)\Rightarrow 10+h=\frac{2420\times 7}{440}=\frac{77}{2}$

$\Rightarrow h=\frac{77}{2}-10=\frac{57}{2}=28.5cm$

$\therefore$ Height = $28.5$cm