Question: Who became Hungary's richest citizen at age 36 thanks to a toy he developed?
Answer: Erno Rubik is a Hungarian inventor, architect and professor of architecture. He is best known for the invention of Rubik's Cube, a 3-D combination puzzle that he invented in 1974. As of January 2009, 350 million cubes had been sold worldwide making it the world's top-selling puzzle game. It is widely considered to be the world's best-selling toy.