If A∩B=B , then
A⊆B
B⊆A
A=ϕ
B=ϕ
Only this case is posiible
If A and B are two events such that P (A) ≠0 and
P(BA)=t, then
(a) A⊏B (b) B⊏A (c) B=ϕ (d) A=ϕ