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 6 books, how many shelves does the bookcase have?
Select the correct option.
A) 6  B) 7  C) 8  D) 9  E) 10
Let x be the number of shelves.   11x - 33 = 7(x-1) + 6   4x = 32   x = 8   The answer is 8.
<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 6 books, how many shelves does the bookcase have?