using conditional probability formula to find following probabilities?

Question

a) if P(A)=5/7 and P(B/A) =2/6, then fine P(A∩B) as a fraction in lowest tems.

 

 

 

B) if P(A∩B) =0.09 P(A)=0.2, then find P(B/A) , to the neares hundredth.

Answer 1

To answer these, you need to know the definition of conditional probability:

 

P(B|A) = P(A∩B) / P(A)

 

or

 

P(A∩B) = P(B|A) * P(A)

 

The second form will make the part a) easy to solve, and the first form will solve part b). If you have further questions, please comment.