There are two events A and B. Whenever event B occurs the event A will also occur. But it is not necessary that whenever event A occurs, the event B will also occur.
Now I want to calculate the probability of B given that event A has already occurred, i.e. P(B|A).
Total number of events for B = n(B) Total number of events for A = n(A)
I guess the probability of P(B|A) should be equal to n(B)/n(A). But I am not sure as I am not good at probability.