Rubik's cubes are permutation puzzles, meaning they have to be solved through changing their configuration or position using interchanging elements. There are usually several ways to reach the solution. l The design was originally invented by Ernő Rubik. The cube has 6 colored faces and the goal is to get the same color on each face. The Rubik's cube (3x3x3) was the best selling toy of the 20th century.