I would like to give a question which i could not solve.

Rd sharma class 10 maths exercise-16.1 mensuration.

In tbis question we have to find curved surface area and volume of the cylinder formed from 25 circular plates, each of radius 10.5cm and thickness 1.6 cm form a solid cylinder.

Given,

250 circular plates each with radius 10.5 cm and thickness of 1.6 cm.

As the plates are placed one above the other, the total height becomes = 1.6 x 25 = 40 cm

We know that,

Curved surface area of a cylinder = 2Ï€rh

= 2Ï€ Ã— 10.5 Ã— 40 = 2640 cm2

And, volume of the cylinder = Ï€r2h

= Ï€ Ã— 10.52 Ã— 40 = 13860 cm3

Therefore,

The curved surface area of the cylinder is 2640 cm2 and the volume of the cylinder is 13860 cm3