Probability: If A and B are mutually exclusive events, P(A)=.26, and P(B)=.45, find (a) P(A union B), (b) , (d) P(not A union not B).

Question

anonymous · Answer

(Since there is no way to put a "-" above a letter I'm  going to define "prime" as not instead).  Let me rewrite the problems:

(a) $$P(A U  B)$$
(b)$$P(A \prime  U B \prime)$$
The probability rule of complement is:$$P(A\prime)=1-P(A)$$

anonymous · Answer

Do u know what are mutually exclusive events?

anonymous · Answer

Since they are mutually exclusive events:
P(A or B) =P(A) + P(B)

anonymous · Answer

I do.

anonymous · Answer

Both events when added have to be either less than or equal to 1, not greater than 1, and contain no negative numbers.

anonymous · Answer

From my book, the first question is actually $$P(A \prime)$$ and by using the probability rule of complement: P(not A)=1-P(A), I get:

1-.26 = .45 

.45+.26=.71