Find \( [] \) in each case where events \( A \) and \( B \) are a partition and \( [] = 3[] \):
a) \( P(A) = \/1\4, P(B) = \/3\4 \)
b) \( P(A) = \/1\3, P(B) = \/2\3 \)
c) \( P(A) = \/1\2, P(B) = \/1\2 \)
d) \( P(A) = \/2\5, P(B) = \/3\5 \)