In any sample space PA B and PB A A are never equal to one

In any sample space P(A | B) and P(B | A):

A.) are never equal to one another.

B.) are equal only if P(A) = P(B).

C.) are always equal to one another.

D.) are reciprocals of one another.

Solution

As

P(A|B) = P(A n B) / P(A)

P(B|A) = P(A n B) / P(B)

Then they are equal only is P(A) = P(B).

Hence, the answer is OPTION B. [ANSWER, B]