Ernő Rubik, a professor of architecture, in an attempt to explain to his student the workings of a three-dimensional object created a 3D combination puzzle in the year 1974 that have become the biggest selling toy in the world till date, The Rubik's Cube.
It took Ernő almost a month to solve the puzzle and he still holds that it gives him immense pleasure both as an engineer as well as a designer to know that nobody yet has been able to improve the basic design of the cube or on its engineering.
The biggest known Rubik's cube measuring 3 cubic meters and weighing 500 kg can be found in one of Tennessee state's major cities, Knoxville. It was found that at the height of its popularity, it was played by nearly one-fifth of the world's population.