Question

___ cm is the height of a cylinder whose radius is 14 cm and the total surface area is 2640 sq.cm.

Answer 1

Let r be the radius and h be the height of the cylinder.
Total surface area of cylinder = $2\pi r(r+h)$

$2640=2\times \frac{22}{7}\times 14(14+h)$

2640 = 1232 + 88h

h = $\frac{2640-1232}{88}$

h = $\frac{1408}{88}$

h = 16 cm