Question

The students of a Vidyalaya were asked to participate in a competition for making and decorating penholders in the shape of a cylinder with a base, using cardboard. Each penholder 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?

Answer 1

Cardboard required to make one pen holder = area of base of cylindrical pen holder + surface area of pen holder.

$={\pi r}^2+2\pi rh=(\pi \times 3^2+2\times \pi \times 3\times 10.5){cm}^2=226.1947{cm}^2$

Total cardboard required

$=(226.1947\times 35){cm}^2=7916.81{cm}^2$