If A and B are two events such that P(A)>0 and P(B)≠1 then P(A/B) is equal to (Here, A¯ and B¯ are complements of A and B, respectively)
1−PAB
1−PA¯B
1−P(A∪B)P(B¯)
P(A¯)P(B)
P(A/B)=P(A∩B)P(B¯)=PA∪BP(B¯)=1−P(A∪B)P(B¯)