Einstein wrote this quiz last century. He said that 98% of the people in the world cannot solve the quiz.?

I've solved it before, it's really not that hard, but can be overwhelming because there is so much information at once. Solving it is similar to the strategy of a sudoku or brainsqueeze type of puzzle. A chart will really help you out, fill in what you know and then see what you can deduce. Each deduction will lead you to another until it is solved.