By only shading whole squares and given that is considered different to , how many different ways can a 2x2 grid be shaded?
Consider the following diagrams.
Therefore the number of possible ways to shade a 2x2 square is
1 + 4 + 6 + 4 + 1 = 16.
What about other sized grids?
Can you generalise for any size grid and any number of colours?