Question

The internal measure of a cuboidal room are 12m ×8m× 4m find the total cost of white washing all four walls of a room if the cost of white washing is rupees 5per meter square what will be the cost of white washing if the ceiling of the room is also white washed

Answer 1

Vertical surface area of cuboidal wall = 2(l+b)h
                                                           = 2(12+8)x4
                                                           = 2x20x4
                                                           =160m²
Cost of white washing=5 per m²
                                   =5x160
                                  =800 rupees
Surface area of cuboidal ceiling=lxbxh
                                                  =12x8x4=384m²
∴cost of whitewashing for ceiling=384x5=1920 rupees

∴Total cost of whitewashing=800+1920=2720 rupees