After the surface area of a cube is painted the cube is cut into 64 smaller cubes of same dimensions. How many have no face painted? 1 face painted? 2 faces painted? 3 faces painted?
Note that lateral surface area of a cylinder is the circumference of base x height of cylinder. Can we write lateral surface area of a cuboid as perimeter of base x height of cuboid?
Let the side be x cm.
∴ Total S.A. of the cube =
But the S.A. of the cube = 600 cm2
∴
or
or
∴ The required side of the cube = 10 cm