Tags: Intelligence, Knowledge, Science Fun Quizzes GamesOnly 3 in 99 adults passed this 3rd Grade Solar System quiz. Facebook Prev Article Next Article Mercury, Venus, Earth, Mars… Facebook Prev Article Next Article Related Posts The hardest Cat quiz you’ll ever take. How would you die in the Roman Empire? How well do you know the Vampire Diaries? Which «How I met your mother» character are you? How well do you know women artists? Which Greek god are you? Which Grey’s Anatomy guy should be your boyfriend? Can you guess the celebrity from their childhood photo? What will the name of your first-born child be?