1) Q: You have 12 coins and a balance. One of the 12 coins has a different weight than the others (either heavier or lighter), can you figure out which one it is and whether it is heavier or lighter in 3 weighings? 2) Q: what is greater than god, more evil than the devil, the poor have it, the rich need it, and if you eat it, you'll die what is it? 80% of kindergarten students were able to answer it, while only 17% of stanford university seniors could provide the correct answer.