Answer:
0.70
Explanation:
You want p(A+B) given that p(A) = 0.60, p(B) = 0.25, and p(A·B) = 0.15.
Probability
The relevant formula is ...
p(A+B) = p(A) +p(B) -p(A·B)
p(A+B) = 0.60 +0.25 -0.15
p(A+B) = 0.70
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Additional comment
In the attached Venn diagram, the sum of the numbers inside the circle labeled A is p(A) = 0.45 +0.15 = 0.60. Likewise, the sum of the numbers inside circle B is p(B) = 0.15 +0.10 = 0.25.
As the attachment shows, the event A includes the event 'A and B'. Likewise, event B includes the event 'A and B'. Simply adding the probabilities of A and B will cause p(A and B) to be counted twice.