question: Sarah has 9 books and Joseph had twice the number of Sarah’s books, but he lost 2 of them. How many books does Joseph currently have?
answer: Joseph used to have 9 books * 2 = <<9*2=18>>18 books.
  After he lost 2 books he remained with 18 books – 2 books = <<18-2=16>>16 books.
  #### 16