9514 1404 393
Answer:
mutually exclusive
Explanation:
The formula of interest is ...
P(A or B) = P(A) + P(B) - P(A and B)
Filling in the given values, we have ...
9/10 = 2/5 + 1/2 - P(A and B)
Solving for P(A and B), we get ...
P(A and B) = 2/5 +1/2 -9/10 = 4/10 +5/10 -9/10
P(A and B) = 0
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Events are mutually exclusive when they can never happen at the same time. That is, P(A and B) = 0.
The events A and B are mutually exclusive.