Ok, so i started using that suggestion and got the following...
P( A n B) = P(B)P(A/B)
then I was going to say that P(A n B) = P(B), but I how can I prove that P(A/B)=1 without assuming that A and B are independent.
Show that an event A is independent of every event B if P(A)=0 or P(A)=1.
**I was able to prove the first part of this problem that is that the events are independent when P(A)=0. However I am stuck on the part where P(A)=1.
I have this so far:
P(A n B) = P(A)P(B/A)
=...