True or False: The conditional probability of event A given that event B has occurred is written as P(B\A).

Answer 1

False
The conditional probability of event A given that event B has occured is wriiten as P(A/B).

P(A/B) = P(A intersection B) / P(B).

For more detailes and better understanding:

http://www.futureaccountant.com/probability/

http://www.schoolingkids.com/probability/

Answer 2

Personally, I would write it as P(A|B)