Answer:
0.58 = 58% probability she passes both courses
Step-by-step explanation:
We have two events, A and B.
[tex]P(A \cup B) = P(A) + P(B) - P(A \cap B)[/tex]
In which:
[tex]P(A \cup B)[/tex] is the probability of at least one of these events happening.
P(A) is the probability of A happening.
P(B) is the probability of B happening.
[tex]P(A \cap B)[/tex] is the probability of both happening.
In this question:
Event A: Passes the first course.
Event B: Passes the second course.
The probability she passes the first course is 0.7.
This means that [tex]P(A) = 0.7[/tex]
The probability she passes the second course is 0.67.
This means that [tex]P(B) = 0.67[/tex]
The probability she passes at least one of the courses is 0.79.
This means that [tex]P(A \cup B) = 0.79[/tex]
What is the probability she passes both courses
[tex]P(A \cup B) = P(A) + P(B) - P(A \cap B)[/tex]
[tex]0.79 = 0.70 + 0.67 - P(A \cap B)[/tex]
[tex]P(A \cap B) = 0.58[/tex]
0.58 = 58% probability she passes both courses