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 = 

Area of car board sheet used by 1 competitor = 1584/7 cm²

Area of car board sheet used by 35 competitors = 1584/7 x 35 cm² = 7920 cm²