Question 137
We have 6 different colors and many cubes available. Each cube is painted with all 6 colors, namely each boundary face with 1 color. How many cubes can be colored at most, if each of them is to be colored differently? (If 1 of the colored cubes can be rotated so that the colors of the border faces are arranged in the same way as on the other cube, the two cubes are the same color.)