Test_0510
### 1. Ex. 9.1
Mildred buys 12 oranges for her children, Grace, Mary, and Frank. In how many ways can she distribute the oranges so that Grace gets at least four, and Mary and Frank get at least two, but Frank gets no more than five?

### 2. Combinations with repetition of 3 distinct objects
In how many ways can we select distinct objects $a, b, c$ such that at most $3, 2, 1$ times, respectively?
### 3 ($\S 9.2\ ex\ 9.4$) Combinations without repetition
In how many ways can we select, without repetitions, $r$ objects from $n$ distinct objects?
### 4. ($\S 9.2\ ex\ 9.11$) Combinations with repetition
In how many ways can we select, with repetitions allowed, $r$ objects from $n$ distinct objects?