If A and B are two events such that P(A)=12  and  P(B)=23 then

A≤A∪B,B≤A∪B P(A)≤P(A∪B),             P(B)≤P(A∪B) 12≤P(A∪B),                        23≤P(A∪B)                         From these two               P(A∪B)≥23