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 competitiors with cardboard. If there were 35 competitiors, how much cardboard was required to be bought for the competition?

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 competitiors with cardboard. If there were 35 competitiors, how much cardboard was required to be bought for the competition?

Given,

Radius of each cylindrical pen holder = 3cm

Height = 10.5 cm

So, area of one cardboard = 2πrh+πr²

= πr(2h+r) =

Number of competitors = 35

∴ total area of cardboard needed = 35×226.28 = 7920 cm²

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