Age Food Preference
1. **Stating the problem:**
We have a survey of 75 people with age and food preference data. We want to find how many people aged 25 or less like both spicy and sweet food.
2. **Given data:**
- Total people: 75
- People older than 25: 50
- People 25 or younger: 75 - 50 = 25
- People who like spicy food: 27
- Among spicy food lovers, 7 are 25 or younger
- People who like sweet food: 28
- Among sweet food lovers, 25 are older than 25
- People who like both spicy and sweet: 5
- People who like neither spicy nor sweet: 25
- Among those who like neither, 7 are older than 25
3. **Define variables:**
Let $x$ = number of people 25 or younger who like both spicy and sweet.
4. **Analyze spicy food lovers:**
- Total spicy lovers = 27
- Spicy lovers 25 or younger = 7
- Spicy lovers older than 25 = 27 - 7 = 20
5. **Analyze sweet food lovers:**
- Total sweet lovers = 28
- Sweet lovers older than 25 = 25
- Sweet lovers 25 or younger = 28 - 25 = 3
6. **Analyze people who like neither spicy nor sweet:**
- Total neither = 25
- Neither older than 25 = 7
- Neither 25 or younger = 25 - 7 = 18
7. **Calculate total people 25 or younger:**
- Total 25 or younger = 25
- They are divided into three groups: spicy only, sweet only, both spicy and sweet, and neither.
8. **Calculate people 25 or younger who like spicy only:**
- Spicy 25 or younger = 7
- Among them, $x$ like both spicy and sweet
- So spicy only 25 or younger = $7 - x$
9. **Calculate people 25 or younger who like sweet only:**
- Sweet 25 or younger = 3
- Among them, $x$ like both spicy and sweet
- So sweet only 25 or younger = $3 - x$
10. **Sum of 25 or younger groups:**
$$ (7 - x) + (3 - x) + x + 18 = 25 $$
Simplify:
$$ 7 - x + 3 - x + x + 18 = 25 $$
$$ 28 - x = 25 $$
$$ x = 28 - 25 = 3 $$
11. **Answer:**
The number of people 25 or younger who like both spicy and sweet food is **3**.
**Final answer: B. 3**