If A and B are dependent events, which of these conditions must be true?

P(A and B)=P(A) + P(B)

P(A and B)= P(B)
P(A)

P(B|A)=P(B)

P(A|B)=P(A)

P(B|A) does not equal P(B)

I think its the first one.

Question

If A and B are dependent events, which of these conditions must be true?

P(A and B)=P(A) + P(B)

P(A and B)=  P(B)
                 P(A)

P(B|A)=P(B)

P(A|B)=P(A)

P(B|A) does not equal P(B)

I think its the first one.

mathmale · Answer

Would you mind explaining your reasoning?
Also:  Try eliminating the least likely answers.
It'd be worth your while to look up and copy down for later reference the appropriate formulas for:
1.  Probability of the union, A AND B, when A and B are independent
2.  Probability of the intersection, A OR B, when A and B are independent
3.  Probability of the union when A and B are dependent, 
4.  Probability of the intersection when A and B are dependent
5.  Probability of A, given that B has already happend (conditional probability)

kitkat16 · Answer

I did I went and looked conditional probability and how A and B are dependent vs independent. I actually have changed my answer.