Solution 3.5

[Andropb]

Hi,
I think that you may have confused the definition of independent events for the mutual exclusive events one.
The first implies that: P(A∩B)=P(A)P(B)
The second implies that: A∩B=∅ ; P(A∩B)=0
So I think the answer should be:
P(B)= [P(A∪B) - P(A)] / [1 - P(A)] = 1/3

[DALEE9000]

Yes you are correct, apologies for the error and will amend in my next round of updates.

[Andropb]

Thank you, for your hard work.