Music Preferences
1. **Problem Statement:** We have three music preferences among students: Jazz, Reggae, and Funk.
Given:
- $|J|=30$, $|R|=20$, $|F|=20$
- $|J \cap R|=10$, $|J \cap F|=10$, $|R \cap F|=9$
- $|J \cap R \cap F|=3$
- $|\text{None}|=32$
Find:
(a) Number who liked Jazz only
(b) Number who liked Reggae only
(c) Number who liked Funk only
(d) Total number of students interviewed
2. **Formula and Rules:**
Use the principle of inclusion-exclusion for three sets:
$$|J \cup R \cup F| = |J| + |R| + |F| - |J \cap R| - |J \cap F| - |R \cap F| + |J \cap R \cap F|$$
The number who liked only one type is:
$$|J \text{ only}| = |J| - |J \cap R| - |J \cap F| + |J \cap R \cap F|$$
(similarly for Reggae and Funk)
3. **Calculate Jazz only:**
$$|J \text{ only}| = 30 - 10 - 10 + 3 = 13$$
4. **Calculate Reggae only:**
$$|R \text{ only}| = 20 - 10 - 9 + 3 = 4$$
5. **Calculate Funk only:**
$$|F \text{ only}| = 20 - 10 - 9 + 3 = 4$$
6. **Calculate total who liked at least one type:**
$$|J \cup R \cup F| = 30 + 20 + 20 - 10 - 10 - 9 + 3 = 44$$
7. **Calculate total number of students interviewed:**
$$\text{Total} = |J \cup R \cup F| + |\text{None}| = 44 + 32 = 76$$
**Final answers:**
- (a) Jazz only = 13
- (b) Reggae only = 4
- (c) Funk only = 4
- (d) Total students = 76