Each shelf of a bookcase contained 11 books. If the librarian took out 33 books and rearranged the remaining books so that all shelves but the last one contained 7 books and that last shelf contained 2 books, how many shelves does the bookcase have?  Choose one:
A) 5
B) 6
C) 7
D) 8
E) 9
Let x be the number of shelves.   11x - 33 = 7(x-1) + 2   4x = 28   x = 7   The answer is 7.
<result>C</result>
Each shelf of a bookcase contained 11 books. If the librarian took out 33 books and rearranged the remaining books so that all shelves but the last one contained 7 books and that last shelf contained 2 books, how many shelves does the bookcase have?