1. **Problem:** Find the probability that the secretary is female and the chairman and treasurer are of different genders.
2. **Given:** 15 males, 10 females, total 25 people.
3. **Positions:** chairman, treasurer, secretary (3 distinct positions).
4. **Step 1:** Total ways to choose 3 people for the positions:
$$25 \times 24 \times 23 = 13800$$
5. **Step 2:** Secretary must be female: choose 1 female for secretary:
$$10$$
6. **Step 3:** Chairman and treasurer must be of different genders:
- Chairman male, treasurer female (excluding secretary):
$$15 \times (10 - 1) = 15 \times 9 = 135$$
- Chairman female (excluding secretary), treasurer male:
$$(10 - 1) \times 15 = 9 \times 15 = 135$$
7. **Step 4:** Total favorable ways:
$$10 \times (135 + 135) = 10 \times 270 = 2700$$
8. **Step 5:** Probability:
$$\frac{2700}{13800} = \frac{\cancel{2700} \times 1}{\cancel{2700} \times 5.1111} = \frac{1}{5.1111}$$
Simplify fraction:
$$\frac{2700}{13800} = \frac{2700 \div 300}{13800 \div 300} = \frac{9}{46}$$
**Final answer:** $\boxed{\frac{9}{46}}$ which corresponds to option (E).
Probability Secretary 4Bb801
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.