Answer: Option B
[tex]P(A|B)=0.50[/tex]
Step-by-step explanation:
We look for the conditional probability of A given B.
This is written as:
[tex]P(A|B) = \frac{P(A\ and\ B)}{P(B)}[/tex]
First we must find the probability of A and B
There are 10 students in total. Note that of those 10 students only 2 of them are at the same time in the karate club and in the chess club
Therefore:
[tex]P(A\ and\ B)=\frac{2}{10}[/tex]
There are 10 students in total. Note that of those 10 students only 4 of them are in the chess club
Then:
[tex]P(B)=\frac{4}{10}[/tex]
Finally:
[tex]P(A|B) = \frac{P(0.2)}{0.4}=0.50[/tex]
