A rectangular prism 3cm by \(6\)cm by 8cm is painted mauve and is then cut into 1 cm cubes what is the total unpainted surface area of these cubes
Original painted surface area = 2 ( 3 x 6 + 6x8 + 8x3) 180 cm^2
After making it 1 cm^3 there are 3 x 6 x 8 cubes each with 6 cm^2 surface area = 864 cm^2
864-180 = 684 cm^2 unpainted