Question

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 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

Radius of circular end of cylinder pen holder = 3 cm 

Height of pen holder = 10.5 cm 

Surface area of 1 pen holder =`"CSA of penholder+Area of base of SA of 1 penholder"= 2pirh+pir^2` 

`2pirh+pir^2` 

= `2xx3.14xx3xx10.5+3.14138` 

= `132xx1.5+198/7cm` 

=`198+198/7cm^2` 

=`1584/7cm^2` 

Area of car board sheet used by 1 competitor = `1584/7 cm^2` 

Area of car board sheet used by 35 competitors=`1584/735cm^2=7920cm^2`