The students of a Vidyalaya were asked to participate in a competition for making and decorating pen holders in the shape of a cylinder with a base, using cardboard. Each pen holder was to be of radius 3cm and height 10.5cm. 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?

Explanation

Requirement of cardboard for each competitors=Curved surface area +base area
=`2pirh+pir^2`
=`[(2xx22//7xx3xx10.5)+22//7xx9]`
=`198-28.80`
=`226.28 cm^2`
Requrement of cardboards for `35 `competitors=`35xx26.28`
=`7920 cm^2`