Answer :
Given :
The probability of event A, P(A) = 0.5
The probability of event B, P(B) = 0.4
The probability of event A or B, P(A or B) = 0.9
Solution :
→ The probability of occurance of event A and B :
$$\therefore \text{P(A or B)} = \text{P(A)} + \text{P(B)} – \text{P(A and B)}$$ $$= \text{P(A and B)} = \text{P(A)} + \text{P(B)} – \text{P(A or B)}$$ $$= 0.5 + 0.4 – 0.9$$ $$= 0$$
→ As the probability P(A and B)=0, the event A and B are mutually exclusive event.
