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

Given,

Radius of each cylindrical pen holder = 3 cm

Height = 10.5 cm

So, area of one cardboard = 2πrh+πr

 = πr(2h + r) = \(\cfrac{22}7\times \) 3 \(\times\)24  = 226.28 cm²

Number of competitors = 35

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