Question

A wooden bookshelf has external dimensions as follows: `H e igh t=110c m ,D e p t h=25 c m ,B r e a dt h=85 c m` (See Figure). The thickness of the plank is `5c m` everywhere. The external faces are to be polished and the inner face are to be painted. If the rate of polisheing is `20p a i s ep e rc m^2` find total cost of polishing

Answer 1

Area of polished=area of n walls+area of base.
`=2h(l+b)+l*b`
`=2*24(110+85)+85+110`
`=10295cm^3`
`1cm^2=20/100`
`10295cm^2=20/100*10295=Rs2059`.