Permutation and Combination

1. Mimi has 12 hair clips of different styles. Among of them, 7 are red and 5 are white. Find number ways in each of the following cases.
a) All the hair clips are arranged on a display shelf such that all the white hair clips are put next to each other.
b) All the white hair clips are arranged on the right of a display shelf and all the red hair clips are arranged on the left of a display shelf.

2. There are 4 Japanese books and 9 Chinese books on a shelf. In each of the following cases, find the number of combinations.
a) 2 Japanese books are drawn from the shelf.
b) 3 Chinese books are drawn from the shelf.
c) 4 books are drawn from the shelf.