Exercise 2 Page 847

Events are mutually exclusive when they cannot occur at the same time. Conversely, they are considered overlapping when they have outcomes in common. The following rules apply for the probability of these types of compound events.

Mutually Exclusive Events	Overlapping Events
P(AandB)=0 P(AorB)=P(A)+P(B)	P(AorB)= P(A)+P(B)-P(AandB)

We are told that A and B are mutually exclusive events, that P(A)=0.6, and that P(B)=0.25. With this information, we want to find the value of P(AorB).

P(AorB)=P(A)+ P(B)

SubstituteII

P(A)= 0.6, P(B)= 0.25

P(AorB)= 0.6+ 0.25

AddTerms

Add terms

P(AorB)=0.85