Venn Diagram
1. Stating the problem: There are 41 students in total.
- 15 take Spanish (S)
- 21 take French (F)
- 7 take neither subject.
2. Find the number of students taking both Spanish and French.
Total students taking at least one subject = Total students - Neither = 41 - 7 = 34
Using the formula for union of two sets:
$$|S \cup F| = |S| + |F| - |S \cap F|$$
Substitute values:
$$34 = 15 + 21 - |S \cap F|$$
Simplify:
$$34 = 36 - |S \cap F|$$
So,
$$|S \cap F| = 36 - 34 = 2$$
3. Probability that a randomly chosen student studies French.
Number of French students = 21
Total students = 41
Probability:
$$P(F) = \frac{21}{41}$$
4. Probability that a randomly chosen student does not study Spanish.
Number of students studying Spanish = 15
Number of students not studying Spanish = 41 - 15 = 26
Probability:
$$P(\text{not } S) = \frac{26}{41}$$
5. Probability that a French student studies Spanish.
Number of students studying both = 2
Number of French students = 21
Conditional probability:
$$P(S|F) = \frac{|S \cap F|}{|F|} = \frac{2}{21}$$
6. Probability that a Spanish student does not study French.
Number of Spanish students = 15
Number of students studying both = 2
Number of Spanish students not studying French = 15 - 2 = 13
Conditional probability:
$$P(\text{not } F|S) = \frac{13}{15}$$