If P(A) = 0.7, P(B) = 0.1, and P(A#nn#B)=0, what is P(B|A)? What about P(A|B)?

1 Answer
Daniel L.
Nov 15, 2015

Both conditional probabilities are #0#.

Explanation:

Conditional probability is calculated as:

#P(A//B)=(P(AnnB))/(P(A))# If #P(AnnB)=0# then #P(A//B)# is also zero.

#P(B//A)# can be calculated in the same way (the numerator is also zero).

It can also be explained this way:

If events #A# and #B# cannot occur at the same time (#P(AnnB)=0#) then it is also impossible that #A# happened under condition of #B# or #B# under condition of #A#

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