Web Science/Part2: Emerging Web Properties/Simple statistical descriptive Models for the Web/Number of words needed to understand most of Wikipedia/quiz

{We saw that more than half of the unique word tokens on Simple English Wikipedia occured only once. Which of the following statements are true?} - picking a random word from the simple english wikipedia the chance is higher than 50% that it occured only once - picking 100 random words from wikipedia we expect more than 50 of them to occure only once + picking a random word the chance for getting a word that occurs only once is less than 10%