Probability Question 231

Question: If two events A and B are such that $ P(A+B)=\frac{5}{6}, $

$ P(AB)=\frac{1}{3} $ and $ P(\bar{A})=\frac{1}{2}, $ then the events A and B are

Options:

A) Independent

B) Mutually exclusive

C) Mutually exclusive and independent

D) None of these

Show Answer

Answer:

Correct Answer: A

Solution:

We have $ P(A+B)=P(A)+P(B)-P(AB) $
$ \Rightarrow \frac{5}{6}=\frac{1}{2}+P(B)-\frac{1}{3}\Rightarrow P(B)=\frac{4}{6}=\frac{2}{3} $

Thus, $ P(A).P(B)=\frac{1}{2}\times \frac{2}{3}=\frac{1}{3}=P(AB) $

Hence events $ A $ and $ B $ are independent.