- #1
zeion
- 466
- 1
Homework Statement
Hi,
I don't understand the proof of this for conditional probability:
If B1, B2, ... are disjoint,
then P(B1, B2, B3, ... | A) = P(B1 | A) + P(B2 | A) + ...
From my notes I only have P(A) > 0 , P(B ∩ A) ≥ 0
but I don't see how those help me prove it..
Homework Equations
The Attempt at a Solution
P(B1, B2, ... | A) = P(B1, B2, B3, ... ∩ A) / P(A)
How do I get +'s out?