1. **Problem statement:** There are 36 people at a gathering from two families: 25 named Lee and 11 named Chan. We select two people at random.
2. **(a) Probability both have the name Lee:**
- Total people: 36
- Number of Lee: 25
- Number of ways to choose 2 people: $\binom{36}{2} = \frac{36 \times 35}{2} = 630$
- Number of ways to choose 2 Lee: $\binom{25}{2} = \frac{25 \times 24}{2} = 300$
- Probability both are Lee:
$$P = \frac{\binom{25}{2}}{\binom{36}{2}} = \frac{300}{630} = \frac{10}{21}$$
3. **(b) Probability they are married to each other:**
- Lee married couples: 8 couples (16 people)
- Chan married couples: 3 couples (6 people)
- Total married couples: 8 + 3 = 11 couples
- Number of ways to choose 2 people: 630 (as above)
- Number of ways to choose a married couple: 11 (each couple is a unique pair)
- Probability:
$$P = \frac{11}{630}$$
4. **(c) Probability they are a man and a woman with the same name:**
- Lee single men: 4, single women: 5
- Lee married couples: 8 couples (each couple has 1 man and 1 woman)
- Chan single men: 2, single women: 3
- Chan married couples: 3 couples
- Number of man-woman pairs with same name:
- Lee singles: $4 \times 5 = 20$
- Lee married couples: 8 (each couple is man-woman pair)
- Chan singles: $2 \times 3 = 6$
- Chan married couples: 3
- Total man-woman pairs with same name:
$$20 + 8 + 6 + 3 = 37$$
- Total ways to choose 2 people: 630
- Probability:
$$P = \frac{37}{630}$$
Probability Names 66055C
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.