6 A library contains 4 identical copies of book \(A , 2\) identical copies of book \(B\) and 5 identical copies of book \(C\). These 11 books are arranged on a shelf in the library.
- Calculate the number of different arrangements if the end books are either both book \(A\) or both book \(B\).
- Calculate the number of different arrangements if all the books \(A\) are next to each other and none of the books \(B\) are next to each other.