To find : The probability of neither A nor B i.e. find P(A∩B) We Know that P(A∩B)=1−P(A∪B) .......(1) Given, The probability of happening of an event A is 0.5 and that of B is 0.3 A and B are mutually exclusive events. ⇒P(A∩B)=0 We know P(A∪B)=P(A)+P(B)−P(A∩B) ⇒P(A∪B)=0.3+0.5 ⇒P(A∪B)=0.8 Equation (1) becomes P(A∩B)=1−0.8=0.2