the way he puts it is very awkward. P(A) == ??? probability of success occuring on first attempt and P(B) == probability of success on second try ? If so, it wo

the way he puts it is very awkward. P(A) == ??? probability of success occuring on first attempt and P(B) == probability of success on second try ? If so, it works P(A or B) = P(A) occurs or P(A) fail (first attempt) and P(B) success (second attempt, you need to fail the first attempt to try a second time). So p(A or B) = P(A) + (1 - P(A))P(B) = P(A)+P(B)-P(A)P(B)=P(A)+P(B)-P(A and B)...