Question

What is the probability of P(A)=1/2 , P(B|A) = 63/100 , P (A n B) = ?

Answer 1

The conditional probability formula states that given events A and B,

`P(A|B)=(P(A\cap B))/(P(B))`

Therefore, in our case,

`\begin{gathered} P(B|A)=(P(A\cap B))/(P(A)) \\ \Rightarrow P(A\cap B)=P(B|A)*P(A)=(63)/(100)*(1)/(2)=(63)/(200) \end{gathered}`

Thus, the answer is 63/200=0.315