Daniel is painting the walls and ceiling of a cuboidal hall with length, breadth and height of 15 m, 10 m and 7 m respectively. From each can of paint 100 m² of area is painted. How many cans of paint will she need to paint the room ?

Area to be painted  = [Area of 4-walls] + Area of ceiling
                               = 2[Perimeter x Height] + l x b
                               = 2[(15+10) x 7] + 15 x 10 m²
                               = 2[25 x 7] + 150 m²
                               = 2 x 175 + 150 m²
                               = 350 + 150 m²
                               = 500 m²
Since 1 can of paint covers 100 m² area.
∴  Number of cans required  =