# 25 circular plates, each of radius 10.5 cm and thickness 1.6 cm,

Question:

25 circular plates, each of radius 10.5 cm and thickness 1.6 cm, are placed one above the other to form a solid circular cylinder. Find the curved surface area and the volume of the cylinder so formed.

Solution:

We have 25 circular plates, each with radius = 10.5 cm and thickness = 1.6 cm

These plates are stacked on top of one another.

So, the total height of the arrangement becomes $=1.6 \times 25=40 \mathrm{~cm}$

Volume of this arrangement $=\pi r^{2} h=\pi(10.5)^{2} \times 40=13860 \mathrm{~cm}^{3}$

Curved surface area $=2 \pi r h=2 \pi \times 10.5 \times 40=2640 \mathrm{~cm}^{2}$

Hence volume $=13860 \mathrm{~cm}^{3}$ and C.S.A $=2640 \mathrm{~cm}^{2}$