The diameter of a cylinder is 28 cm and its height is 40 cm.

Here, r = 28/2 = 14 cm; h = 40 cm

Curved surface area of the cylinder $=2 \pi r h$

$=2 \times \frac{22}{7} \times 14 \times 40 \mathrm{~cm}^{2}$

$=2 \times 22 \times 2 \times 40 \mathrm{~cm}^{2}$

$=3520 \mathrm{~cm}^{2}$

Total surface area of the cylinder $=2 \pi r h+2 \pi r^{2}$

$=\left(3520+2 \times \frac{22}{7} \times 14^{2}\right) \mathrm{cm}^{2}$

$=(3520+1232)=4752 \mathrm{~cm}^{2}$

$\therefore$ Volume of the cylinder $=\pi r^{2} h$

$=\frac{22}{7} \times 14^{2} \times 40 \mathrm{~cm}^{3}$

$=22 \times 14 \times 2 \times 40 \mathrm{~cm}^{3}$

$=24640 \mathrm{~cm}^{3}$