Question

the student of school were asked to participate in competition for making and decorating pen holder in the shape of cylinder with a base using cardboard . Each pen holder be to radius 3cm and height 10.5cm . the school 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

First find the surface area of a pen holder.
The top will be excluded because it is open from top
So formula =  $\pi$$r^{2}$ + 2$\pi$rh
(take $\pi$ = 3.14)
=28.26 + 197.82 = 226[tex]cm^2[tex](approx)
surface area of 35 such pen holders = 35 * 226[tex]cm^2[tex] = 7910[tex]cm^2[tex]

Therefore 7910[tex]cm^2[tex] of cardboard is required