Question

The students of a Vidyalaya were asked to participate in a competition for making and decorating penholders in the shape of a cylinder with a base, using card-board. Each penholder was to be of radius 3 cm and height 10.5 cm. The Vidyalaya was to supply the competitors with cardboard. If there were 35 competitors, how much cardboard was required to be bought for the competition?

Answer 1

Penholder is in the shape of a cylinder, which one of the edges is open and another is closed. 

radius, r = 3 cm, height, h = 10.5 cm. 

Total cardboard required by one Competitor: = Curved Surface Area + Area of bottom 

= 2πrh + πr²

∴ Total cardboard required for 35 competitors is :