Rubik invented cube that bears his name as teaching aid for his class of students . : How long did it take you to solve the cube once you 'd created the prototype ? The colorful puzzle has gone on to become the world 's biggest selling toy -- with 350 million sold . Comment:
Rubik invented cube that bears his name as teaching aid for his class of students . The colorful puzzle has gone on to become the world 's biggest selling toy -- with 350 million sold . Comment: